Citation Nr: 1757745 Decision Date: 12/13/17 Archive Date: 12/28/17 DOCKET NO. 12-30 135 DATE THE ISSUES 1. Entitlement to service connection for residuals of heat exhaustion. 2. Entitlement to service connection for liposarcoma, left calf status post chemotherapy and reconstructive surgery. 3. Entitlement to service connection for sickle cell trait. ORDER Service connection for residuals of heat exhaustion is denied. Service connection for liposarcoma, left calf status post chemotherapy and reconstructive surgery is denied. Service connection for sickle cell trait is denied. FINDINGS OF FACT 1. The Veteran has no diagnosis of residuals of heat exhaustion. 2. The Veteran's liposarcoma was neither incurred in service nor manifested within one year of service discharge and is not otherwise etiologically related to active service. 3. The Veteran's sickle cell trait is a congenital defect that was not subject to a superimposed injury or disease in service. CONCLUSIONS OF LAW 1. The criteria for service connection for residuals of heat exhaustion have not been met. 38 U.S.C. §§ 1110, 1112, 1113, 1131, 5107(b) (2012); 38 C.F.R. §§ 3.102, 3.303 (2017). 2. The criteria for service connection for liposarcoma, left calf status post chemotherapy and reconstructive surgery, have not been met. 38 U.S.C. §§ 1110, 1112, 1113, 1131, 5107(b) (2012); 38 C.F.R. §§ 3.102, 3.303, 3.307, 3.309(a) (2017). 3. The criteria for service connection for sickle cell trait have not been met. 38 U.S.C. §§ 1110, 1112, 1113, 1131, 5107(b) (2012); 38 C.F.R. §§ 3.102, 3.303(c), 3.306 (2017). REASONS AND BASES FOR FINDINGS AND CONCLUSIONS The Veteran served active duty and reserve from October 1970 to July 2006. This matter comes before the Board of Veterans' Appeals (Board) on appeal from a April 2010 rating decision of the Department of Veterans Affairs (VA) Regional Office in New Orleans, Louisiana (RO). In January 2017, the Board remanded this matter for further development, and the case has been returned for appellate consideration. The Board finds there has been substantial compliance with its January 2017 remand directives. See D'Aries v. Peake, 22 Vet. App. 97, 105 (2008); see also Dyment v. West, 13 Vet. App. 141, 146-47 (1999) (holding that there was no Stegall (Stegall v. West, 11 Vet. App. 268 (1998)) violation when the examiner made the ultimate determination required by the Board's remand). This appeal was processed using the Virtual VA (VVA) and Veterans Benefits Management System (VBMS) paperless claims processing systems. Accordingly, any future review of this Veteran's case should take into consideration the existence of these electronic records. Veterans Claims Assistance Act of 2000 As required by the Veterans Claims Assistance Act of 2000 (VCAA), VA has a duty to notify and assist veterans in substantiating claims for VA benefits. 38 U.S.C. §§ 5100, 5102, 5103, 5103A (2012); 38 C.F.R. § 3.159(b) (2017). The Veteran has not raised any issues with the duty to notify or duty to assist. See Scott v. McDonald, 789 F.3d 1375, 1381 (Fed. Cir. 2015) (holding that "the Board's obligation to read filings in a liberal manner does not require the Board . . . to search the record and address procedural arguments when the veteran fails to raise them before the Board."); Dickens v. McDonald, 814 F.3d 1359, 1361 (Fed. Cir. 2016) (applying Scott to a duty to assist argument). As such, the Board will now review the merits of the Veteran's claims. Law and Analysis The Veteran essentially contends that he has residuals of heat exhaustion and liposarcoma that were caused by his active service and that service aggravated his sickle cell trait. In general, service connection may be granted for a disability or injury incurred in or aggravated by active military service. 38 U.S.C. § 1110 (2012); 38 C.F.R. § 3.303 (2017). To prevail on a direct service connection claim, there must be competent evidence of (1) a current disability, (2) an in-service incurrence or aggravation of a disease or injury, and (3) a nexus between the in-service disease or injury and the current disability. Holton v. Shinseki, 557 F.3d 1362, 1366 (Fed. Cir. 2009); 38 U.S.C. §§ 1110, 1131 (2012); 38 C.F.R. § 3.303(a) (2017). For certain enumerated chronic diseases, such as malignant tumors, service connection may be granted based upon a presumption of incurrence in or aggravation by service despite the lack of evidence of such disease during service if diagnosed and manifested to a compensable degree within a prescribed period, generally one year, after separation from qualifying service. 38 C.F.R. §§ 3.303(b), 3.307, 3.309(a) (2017); see Combee v. Brown, 34 F.3d 1039 (Fed. Cir. 1994); see also Walker v. Shinseki, 708 F.3d 1331, 1338 (Fed. Cir. 2013) (constraining § 3.303(b) to those chronic diseases listed in § 3.309(a)). Additionally, for those same enumerated chronic diseases service connection may be granted despite the lack of evidence of such disease during service if there is a combination of manifestations sufficient to identify the disease entity, and sufficient observation to establish chronicity at the time, as distinguished from merely isolated findings or a diagnosis including the word "chronic.": 38 C.F.R. § 3.303(b) (2017); see 38 C.F.R. § 3.309(a) (2017); Walker v. Shinseki, 708 F.3d 1331 (Fed. Cir. 2013). When the fact of chronicity in service is not adequately supported, then a showing of continuity after discharge is required to support the claim. There must be competent medical evidence unless the evidence relates to a condition as to which lay observation is competent to identify its existence. 38 C.F.R. § 3.307(b) (2017). In making determinations, VA is responsible for ascertaining whether the evidence supports the claim or is in relative equipoise, with the veteran prevailing in either event, or whether the preponderance of the evidence is against the claim, in which case the claim is denied. See 38 U.S.C. § 5107 (2012); 38 C.F.R. § 3.102 (2017); Gilbert v. Derwinski, 1 Vet. App. 49, 54 (1990). Here, the Board reviewed all evidence in the claims file, with an emphasis on that which is relevant to this appeal. Although the Board has an obligation to provide reasons and bases supporting its decision, there is no need to discuss, in detail, every piece of evidence of record. Gonzales v. West, 218 F.3d 1378, 1380-81 (Fed. Cir. 2000) (holding that the Board must review the entire record but does not have to discuss each piece of evidence). Therefore, the Board will summarize the relevant evidence where appropriate, and the Board's analysis will focus specifically on what the evidence shows, or fails to show, as it relates to the Veteran's claims. As to all the claims, the Board acknowledges that in a March 2010 memorandum the RO made a formal finding that a complete set of the Veteran's service treatment records is unavailable. In a March 2010 letter, the RO advised the Veteran. Also, from the outset, the Board notes that the Veteran, while entirely competent to report his symptoms, is not competent to proffer an opinion as to diagnoses or the etiologies of his disabilities. Such opinions require specific medical training and are beyond the competency of a lay person. In the absence of evidence indicating that the Veteran has the medical training to render medical opinions, the Board must find that his contentions in these regards to be of no probative value. See 38 C.F.R. § 3.159(a)(1)-(2) (2017) (defining competent medical evidence and competent lay evidence); Charles v. Principi, 16 Vet. App. 370 (2002) (finding the veteran competent to testify to symptomatology capable of lay observation); Layno v. Brown, 6 Vet. App. 465, 469-70 (1994) (noting that competent lay evidence requires facts perceived through the use of the five senses); Barr v. Nicholson, 21 Vet. App. 303, 307 (2007) (stating that "lay persons are not competent to opine on medical etiology or render medical opinions."). Accordingly, the statements offered by the Veteran in support of his claims are not competent evidence to support any specific diagnosis or etiology of a disability. Residuals of Heat Exhaustion The Veteran essentially contends that he has residuals of heat exhaustion that should be service connected. The Board finds that competent, credible, and probative evidence establishes that the Veteran does not have residuals of heat exhaustion. With respect to the first Holton element, current disability, the Veteran's medical treatment records show a history of recurrent episodes of dizziness and fainting spells. His medical records from Dr. J.T.F. show that in December 1988 he was seen the day after having a dizziness and fainting spell. The assessment was to rule out postural hypotension. The records show that in April 2000, the Veteran was seen for headache and dizziness for which he was prescribed AntiVert. The Veteran's medical treatment records show that in October 2008, while he was taking his third cycle of chemotherapy for liposarcoma, the Veteran had an episode of syncope with an episode of vomiting. It was noted that the Veteran may have been mildly dehydrated. He was found to have non-neutropenic fever and was hospitalized for six days. Due to associated cough and achiness, he was treated with antibiotics for questionable pneumonia. During a November 2008 medical consultation, the Veteran reported that he had had dizziness and lightheadedness before when he got too heated up. He and his wife reported that he would get flushed and dizzy and would have to sit down. The Veteran was advised to monitor his blood pressure and to look for trends of possible hypotension that would cause his syncope. The Veteran's medical records show that during a May 2009 consultation with Dr. B.K., the Veteran reported that his work as a mechanical engineer required him to be in the field where he had to walk for long periods of time and do other activities in extreme temperatures. The Veteran explained that he was limited by his sickle cell trait because he would become lightheaded and heat sensitive. A September 2009 report of a tilt table test shows that the Veteran was clinically positive for vasodepressor syncope, although his systolic blood pressure fall did not seem consistent. In an October 2009 generic cover letter, addressing the Veteran's degree of disability and summarizing his course of care at the facility, Dr. B.K. noted that, after cardiology workup, the Veteran was diagnosed as having cardiac arrhythmia with vasodepressor syncope. In April 2017, the Veteran was afforded a VA examination for seizure disorders, epilepsy. The examination included an in-person examination and complete review of the Veteran's claims file, including the Board's January 2017 remand. The Veteran reported that he was not aware of any seizures but that he had a couple of episodes of passing out, remembering getting overheated, and that he, currently, is sensitive to extremely hot weather. The examiner indicated on the report that the Veteran had not been diagnosed with a seizure disorder. The Veteran is competent to report his symptoms, and in this case, the Veteran did not report any symptoms of residuals of heat exhaustion, rather, he merely remembered having a couple of episodes of passing out in the heat. See 38 C.F.R. § 3.159(a)(2)(2017). Furthermore, the April 2017 VA examination report shows that the Veteran has no diagnosis related to residuals of heat exhaustion. The Board concludes, therefore, that the first Holton element is not met, and the claim fails. See Brammer v. Derwinski, 3 Vet. App. 223, 225 (1992) (stating that "[i]n the absence of proof of a present disability there can be no valid claim."); see also Romanowsky v. Shinseki, 26 Vet. App. 289, 293-94 (2013) (interpreting McClain v. Nicholson, 21 Vet. App. 319 (2007)). For completeness of analysis of the evidence of record, the Board will consider the remaining Holton elements. With regards to the second Holton element, in-service incurrence or aggravation of a disease or injury, the Veteran's responses on reports of medical history in his service treatment records present ambiguity. On his December 1969 pre-induction report of medical history the Veteran did not indicate having had dizziness or fainting spells. On his February 1971 report of medical history when leaving active duty, the Veteran indicated that he had had dizziness or fainting spells. On his January 1976 quadrennial report of medical history for the reserves, the Veteran indicated that he had not had dizziness or fainting spells. The Board finds that the second Holton element is met. With respect to the third Holton element, medical nexus, this was addressed by the April 2017 VA examination report and associated medical opinion. The examiner remarked that the Veteran had an episode of heat exhaustion due to exposure to extremes of heat that caused dehydration. It was stated that symptoms of dehydration include dizziness and fainting and that they resolve with fluids and cool environment; also, episodes of heat exhaustion are preventable. In the medical opinion to the April 2017 examination, the examiner opined that it was less likely than not that the Veteran's claimed condition of residuals to heat exhaustion incurred in or was caused by service. The examiner explained that, after a review of the Veteran's medical records and claims file, there was no evidence that the Veteran has had any residuals from previous episodes of heat exhaustion. The examiner explained that heat exhaustion is preventable through adequate hydration and avoidance of extreme heat. The examiner noted that sickle cell trait is listed in the medical literature as a risk factor for heat related illness, which means that the Veteran has to be extra careful. The examiner opined that the episodes of dizziness and fainting in service were likely signs of dehydration caused by heat exhaustion, and those symptoms resolved when the Veteran was treated with liquids and placed in a cool environment. In a July 2017 addendum medical opinion, the examiner explained that the Veteran experienced a bout of heat exhaustion on active duty as a result of his environmental working conditions, which the Veteran had an increased risk of due to sickle cell trait. As a result, the Veteran had to take precautionary measures to avoid heat exhaustion. While the claim also fails for failing to meet the third Holton element, as just stated, the Board notes that the Veteran's post-service medical treatment records contain reports and treatment of dizziness and fainting spells. While the Board is prohibited from exercising its own independent judgment to resolve medical questions, see Colvin v. Derwinski, 1 Vet. App. 171, 175 (1991), the Board finds that the medical records provide contemporaneous explanations for the events in the context of the Veteran's medical condition at the time, which did not relate to service or any service-connected disability. Because the evidence of record does not indicate that the Veteran's persistent dizziness and fainting spells may be associated with service or another service-connected disability, remand for further development is not warranted. See McLendon v. Nicholson, 20 Vet. App. 79, 81 (2006). Based upon the foregoing, as the preponderance of the evidence is against the claim, the benefit of the doubt rule does not apply, and the claim must be denied. See 38 U.S.C. §§ 501, 5107(b) (2012); 38 C.F.R. §§ 3.102, 4.3, 4.7 (2017); see also Gilbert v. Derwinski, 1 Vet. App. 49, 54 (1990). Liposarcoma The Veteran contends that his liposarcoma was caused by his active service and that it should be service connected. The Board finds that competent, credible, and probative evidence establishes that the Veteran's liposarcoma was not incurred in and, therefore, is not etiologically related to the Veteran's active service. With respect to the first Holton element, current disability, the Veteran was afforded a VA examination in April 2017, during which he was diagnosed as having left calf myxoid liposarcoma, status post chemotherapy and resection with reconstructive surgery. Accordingly, the first Holton element is met. With respect to the second Holton element, in-service incurrence or aggravation of a disease or injury, the Veteran's service treatment records are silent for any symptoms, complaints, diagnosis, or treatment for a left calf muscle condition. Furthermore, the Veteran does not contend otherwise. The April 2017 VA examination report shows that the Veteran reported that his wife noticed that his left calf was larger than the right, which led to medical investigation, diagnosis, and treatment in 2008. This was more than one year after the Veteran was discharged from active duty. Accordingly, the second Holton element is not met, and the claim fails as to a showing of an in-service incurrence or aggravation of a disease or injury. With respect to the third Holton element, medical nexus, in the absence of evidence of in-service incurrence or aggravation of a disease or injury, a medical nexus opinion would seem to be an impossibility. In an October 2012 letter to VA, Dr. B.K. summarized the course of the Veteran's liposarcoma care. He stated that it would be difficult to establish the etiology of the Veteran's liposarcoma. He concluded the letter: "I have had him on a medical disability since 2009. I feel that-pending your requirements-he continues to meet criteria for a medical disability and by extension a military disability as well." A thorough reading of Dr. B.K.'s medical records for the Veteran spanning years reveals that Dr. B.K. provided considerable assistance and support to the Veteran in regards to filing claims and paperwork for disability, including short-term, long-term, and permanent, from sources including insurance companies, Social Security Administration, and Veterans Affairs. Dr. B.K.'s detailed notes make it clear that it was his medical opinion that the Veteran's ongoing medical improvement was contingent upon him not going back to his former employment as a mechanical engineer due to the strenuous physical requirements of the job. In the medical opinion of the April 2017 VA examination, the examiner opined that the Veteran's liposarcoma did not manifest itself while the Veteran was on active duty, not being diagnosed until 2008. The examiner opined that it was less likely than not that it incurred in or was caused by service. The examiner explained that there was nothing in the Veteran's records to indicate that he had an environmental exposure while on active duty that would cause this rare cancer of muscle tissue and that the medical literature does not support a link between this cancer and military service. In a July 2017 addendum medical opinion, the examiner opined that it is less likely as not that the Veteran's liposarcoma had its onset in service or is otherwise related to service, referencing the lack of evidence in the Veteran's service treatment records and a diagnosis made years after separation from active duty. The examiner explained that the medical literature indicates that the causes of liposarcoma are not clear but that there is a genetic component, meaning the Veteran was born with a propensity to develop the condition. The examiner provided medical citation to support the analysis. The examiner pointed out that in Dr. B.K.'s October 2012 letter, Dr. B.K. did not link the Veteran's liposarcoma to the Veteran's service. The examiner explained, rather, Dr. B.K. opined that the Veteran met the criteria for being medically disabled as a result of his liposarcoma and, provided that the Veteran met the other criteria, this disability should extend to military disability. The Board finds that the VA examiner's reading of Dr. B.K.'s October 2012 letter is supported by the record and that Dr. B.K.'s letter cannot be construed as a nexus statement supporting a relationship between the Veteran's liposarcoma and active service. See Nieves-Rodriguez v. Peake, 22 Vet. App. 295, 300-04 (2008); Prejean v. West, 13 Vet. App. 444, 448-49 (2000) (stating that factors for assessing the probative value of a medical opinion include the thoroughness and detail of the opinion). The Board finds that the intent of the letter was to support the element of current disability only. Accordingly, the third Holton element is not met, and the claim fails. Based upon the foregoing, as the preponderance of the evidence is against the claim, the benefit of the doubt rule does not apply, and the claim must be denied. See 38 U.S.C. §§ 501, 5107(b) (2012); 38 C.F.R. §§ 3.102, 4.3, 4.7 (2017); see also Gilbert v. Derwinski, 1 Vet. App. 49, 54 (1990). Sickle Cell Trait The Veteran contends that his sickle cell trait was aggravated by his active service and should be service connected. The Board finds that competent, credible, and probative evidence establishes that the Veteran's sickle cell trait but heat exhaustion experienced during service was not an aggravation of the condition because heat exhaustion is preventable. At the time of a service entrance examination, every Veteran shall be taken to have been in sound condition when examined, accepted, and enrolled for service, except as to defects, infirmities, or disorders noted at the time of the examination, acceptance, and enrollment, or where clear and unmistakable (obvious or manifest) evidence demonstrates that the injury or disease existed before acceptance and enrollment and was not aggravated by such service. 38 U.S.C. § 1111 (2012); 38 C.F.R. § 3.304(b) (2017). This statutory provision is referred to as the presumption of soundness. Horn v. Shinseki, 25 Vet. App. 231, 234 (2012). Only such conditions as are recorded in examination reports are considered as noted. 38 C.F.R. § 3.304(b) (2017). When determining whether a defect, infirmity, or disorder is noted at entrance into service, supporting medical evidence is needed; the Veteran's reporting of preservice medical history at the time of induction does not constitute a notation of those conditions. Crowe v. Brown, 7 Vet. App. 238, 245 (1994). The presumption of soundness may only be rebutted by clear and unmistakable evidence that the Veteran's disability was both preexisting and not aggravated by service. 38 C.F.R. § 3.304(b) (2017); Wagner v. Principi, 370 F.3d 1089 (Fed. Cir. 2004). VA's General Counsel has reinforced that the presumption of soundness is rebutted only where clear and unmistakable evidence shows that the condition existed prior to service and that it was not aggravated by service. VAOPGCPREC 3-2003; Horn v. Shinseki, 25 Vet. App. 231, 236 (2012). The General Counsel concluded that 38 U.S.C. § 1111 requires VA to bear the burden of showing the absence of aggravation in order to rebut the presumption of sound condition. See Wagner v. Principi, 370 F.3d 1089, 1095 (Fed. Cir. 2004). Therefore, where there is evidence showing that a disorder manifested or was incurred in service, and this disorder is not noted on the Veteran's entrance examination report, the presumption of soundness operates to shield the Veteran from any finding that the unnoted disease or injury preexisted service. See 38 C.F.R. § 3.304 (b) (2017); Gilbert v. Shinseki, 26 Vet. App. 48, 52-53 (2012). While a veteran's statements reporting medical history at the time of enlistment do not create a notation of a preexisting condition, thereby permitting the presumption of soundness to attach, VA can use those statements as evidence to rebut the presumption. Horn v. Shinseki, 25 Vet. App. 231, 237-8 (2012); Harris v. West, 203 F.3d 1347 (Fed. Cir. 2000). The statute does not limit what kind of evidence VA can use to rebut the presumption, and VA may consider records concerning the inception of a condition made before, during, or after service. Harris v. West, 203 F.3d 1347, 1349-50 (Fed. Cir. 2000). "While contemporaneous clinical evidence or recorded history may often be necessary to satisfy the heavy burden of rebutting the statutory presumption of soundness, . . . there is no absolute rule in the statute, the regulation, or the case law requiring such evidence before the presumption can be rebutted." Harris v. West, 203 F.3d 1347, 1351 (Fed. Cir. 2000). A preexisting injury or disease will be considered to have been aggravated by active military, naval or air service, where there is an increase in disability during such service, unless there is a specific finding that the increase in disability is due to the natural progression of the disease. 38 C.F.R. § 3.306(a) (2016); see Maxson v. West, 12 Vet. App. 453, 458-9 (1999) (applying the definition used for the presumption of aggravation to the second element for service connection under Caluza v. Brown, 7 Vet. App. 498 (1995)); Hunt v. Derwinski, 1 Vet. App. 292 (1991). A defect considered by medical authorities to be of congenital origin must by its very nature have preexisted a claimant's military service. See VAOPGCPREC 82-90; see also 38 C.F.R. §§ 3.303(c) (2017). Accordingly, congenital and developmental defects are not diseases or injuries within the meaning of applicable legislation for VA disability compensation purposes, and no additional or confirmatory evidence is necessary. 38 C.F.R. §§ 3.303(c), 4.9 (2017). Nevertheless, service connection may be warranted for a disability resulting from a superimposed injury or disease occurring during active service. VAOPGCPREC 82-90. VA's General Counsel has held that there is a distinction under the law between a congenital or developmental disease and a congenital defect for service connection purposes. Service connection may be granted for diseases (but not defects) of congenital, developmental, or familial origin if the evidence as a whole shows that the manifestations of the disease in service constituted aggravation of the disease within the meaning of applicable VA regulations. 38 C.F.R. § 3.306 (2017); VAOPGCPREC 82-90. Sickle cell trait is the heterozygous form of sickle cell anemia, characterized by the presence of both hemoglobin S and hemoglobin A in red blood cells. Anemia and the other signs of sickle cell anemia do not occur. People who have the trait are informed of and counseled about the possibility of having a child with sickle cell disease if both parents have the trait. Sickle cell trait, Mosby's Medical Dictionary (8th ed. 2009), https://medical-dictionary.thefreedictionary.com/sickle+cell+trait (retrieved Dec. 4, 2017). VA regulations direct that sickle cell trait alone, without a history of directly attributable pathological findings, is not a ratable disability. 38 C.F.R. § 4.117, Diagnostic Code 7714, n. (2017). Since sickle cell trait is a congenital condition, the presumption of soundness at service entrance is rebutted without further medical evidence. See 38 U.S.C. § 1111 (2012); 38 C.F.R. § 3.303(c) (2017). The relevant evidence includes the Veteran's service treatment records which show that on his December 1969 pre-induction report of medical history he disclosed that he had contact with a medical professional in Colorado in the past five years. On his February 1971 report of medical history, he disclosed that he had contact with a medical professional in Ohio. The Veteran's service treatment records do not contain evidence of the nature of those contacts, and otherwise, there is no evidence that the Veteran had been diagnosed as having sickle cell trait prior to or during service. Additionally, the Veteran's service treatment records are silent for symptoms, complaints, treatment, or diagnosis related to sickle cell trait or anemia. In April 2017, the Veteran was afforded a VA examination for hematologic and lymphatic conditions, during which the examiner diagnosed sickle cell trait, noting that the diagnosis was made in 1970 and that the Veteran does not have sickle cell anemia. The examiner stated that sickle cell trait is a congenital defect. As to whether this congenital defect had been subject to superimposed disease or injury during service, the examiner opined that there was no documented evidence that the Veteran had any adverse effects during service as a result of his sickle cell trait. The examiner opined that because there was no information in the Veteran's service treatment records to support aggravation of the condition, the Veteran's sickle cell trait was clearly and unmistakably not aggravated by service. In a July 2017 addendum medical opinion, the examiner explained that sickle cell trait is a congenital disease and indicated that, as a result, it clearly and unmistakably existed prior to service. The examiner noted that the Veteran's service treatment records are silent as to this diagnosis. The examiner opined that the evidence showed that the Veteran's sickle cell trait clearly and unmistakably was not aggravated during service; rather, because of the sickle cell trait, the Veteran must take precautionary measures to avoid heat exhaustion by staying well-hydrated and avoid long-term heat exposure. The Board finds that the Veteran's sickle cell trait is a congenital defect that was not subject to a superimposed disease or injury in service. The record is silent for any treatment related to the Veteran's sickle cell trait during as well as after service. Although the Veteran may believe that his sickle cell trait was aggravated during service, due to the nature of this condition, an evaluation of whether the pathology worsened is better explained by a medical professional as it is a complex assessment. See Woehlaert v. Nicholson, 21 Vet. App. 456 (2007). Here, the VA examiner opined that the Veteran experienced heat exhaustion while in service, which was explained was preventable and not related to the Veteran's sickle cell trait. The Board finds that this medical opinion is the most probative as it is factually accurate, fully articulated, and based on sound reasoning. See Nieves-Rodriguez v. Peake, 22 Vet. App. 295 (2008). (CONTINUED ON NEXT PAGE) In sum, evidence shows that the Veteran has sickle cell trait. However, service connection is unwarranted because the preponderance of the evidence of record indicates that the Veteran's sickle cell trait is a congenital defect which is not related to service. 38 C.F.R. § 3.303. Further, the evidence is against a finding that there is a superimposed disease or injury on the sickle cell trait during service. As the preponderance of the evidence is against the claim, the claim must be denied. 38 U.S.C.§ 5107 (b); 38 C.F.R. § 3.102. ______________________________________________ LANA K. JENG Veterans Law Judge, Board of Veterans' Appeals ATTORNEY FOR THE BOARD Leanne M. Innet, Associate Counsel Copy mailed to: Disabled American Veterans Department of Veterans Affairs