Appeal from the United States Court of Federal Claims in Case No. 04-VV-1041, Senior Judge Lawrence S. Margolis. Appeal from the United States Court of Federal Claims in Case No. 07-VV-170, Judge Thomas C. Wheeler.
The opinion of the court was delivered by: Bryson, Circuit Judge.
Before RADER, Chief Judge, SCHALL and BRYSON, Circuit Judges.
In separate proceedings, petitioners Jennifer and Gary Stone and petitioner Scott Hammitt sought compensation under the National Vaccine Injury Compensation Program for injuries to their children allegedly caused by the Diphtheria-Tetanus-acellular Pertussis ("DTaP") vaccine. The Stones alleged that the administration of the DTaP vaccine to their daughter Amelia was a substantial cause of a seizure disorder from which she suffers, known as Severe Myoclonic Epilepsy of Infancy ("SMEI").*fn1 Mr. Hammitt made the same allegation with respect to his daughter Rachel, who also suffers from SMEI. The same special master presided over both cases and determined that the petitioners failed to show entitlement to compensation because in both cases the evidence showed that a gene mutation present in both children was the sole cause of their injuries. The Court of Federal Claims affirmed both decisions.
Amelia Stone was born on April 17, 2001, and received a DTaP vaccination on August 27, 2001. The day after her DTaP vaccination, Amelia experienced a febrile seizure. She was treated at a hospital and released several days later. The special master and the trial court found that Amelia suffered no brain damage as a result of the seizure. On September 26, 2001, Amelia experienced a second febrile seizure. She was again treated at the hospital, and no evidence of brain damage was discovered.
Amelia continued to experience seizures, both febrile and afebrile. At a check-up on December 19, 2001, her doctor noted that "[i]t appears now that [Amelia] has a primary seizure disorder," but that her "neurologic development has been appropriate." In October 2003, Amelia's seizure disorder was diagnosed as SMEI. In January 2005, genetic testing revealed that Amelia has a de novo mutation in her SCN1A gene. The records accompanying the results noted that "[t]his finding is most consistent with this DNA variant being associated with a severe phenotype (SMEI or SMEB) rather than a mild or normal phenotype."
Rachel Hammitt was born on November 9, 2003. She received her second DTaP, IPV, Hepatitis B, Hib, and Pneumococcal Conjugate vaccinations on March 15, 2004. That evening, Rachel experienced a febrile seizure. She was treated at a hospital and released several days later. The special master and the trial court found that Rachel suffered no brain damage as a result of that seizure. On April 22, 2004, Rachel experienced a second seizure. She was again treated at the hospital and released several days later.
Thereafter, Rachel continued to experience intermittent seizures. Records from her 12-month check-up on November 12, 2004, showed a diagnosis of epilepsy but reported normal growth and development. However, at her 14-month checkup, Rachel's pediatrician recorded delayed verbal and gross motor development and recommended that she be evaluated for global developmental delays. Genetic testing ordered on May 3, 2005, revealed that Rachel has a mutation in her SCN1A gene. The records accompanying the results stated that the mutation is "associated with a severe phenotype (SMEI or SMEB) rather than a mild or normal phenotype." At a follow-up appointment, a physician noted that Rachel's "clinical course, EEG, and SCN1A test . . . are suggestive of [SMEI]."
The petitioners in both cases sought compensation under the National Childhood Vaccine Injury Act, 42 U.S.C. §§ 300aa-1 to 300aa-34 ("Vaccine Act"), alleging that the DTaP vaccination was a substantial cause of each child's SMEI. The evidence submitted to the special master in both cases was largely the same, and much of it-including key testimony for the respondent concerning the SCN1A gene mutation-was presented in a single consolidated hearing. Dr. Marcel Kinsbourne testified for the petitioners. He testified that in both cases the DTaP vaccinations were a substantial contributing cause of the SMEI. He explained his theory of causation as follows: "The DTaP vaccine[s] [received by Amelia and Rachel] caused [each of them] to have a fever; that fever caused a prolonged seizure classified as a complex febrile seizure; and that seizure damaged [the] brain, lowering [the] level of seizure propensity, thus facilitating further seizures." However, Dr. Kinsbourne agreed that "a trigger doesn't necessarily have to have a further deeper impact," and he admitted that he had simply "inferred" that the children had suffered brain damage from the fact of their initial seizures. He agreed that there was no clinical manifestation of the inferred brain damage in either case.
In support of his theory, Dr. Kinsbourne relied on a series of medical articles, which the special master did not find persuasive. Some of the articles on which Dr. Kins-bourne relied concerned the DTP vaccine, rather than the DTaP vaccine. The special master found those articles unhelpful because neurological reactions to the two different vaccines "do not occur with the same frequency, nor [do they present] the same relative risks." Dr. Kins-bourne also relied on an article by Berkovic et al. to support his theory. The special master, however, found that the Berkovic article supported the respondent's position, not Dr. Kinsbourne's theory, because the authors of that article did not find that vaccines are a "trigger for encephalopathy" as Dr. Kinsbourne argued. Instead, that article concluded that individuals with certain mutations in the SCN1A gene "seem to develop SMEI or SMEB [a related seizure condition] whether or not they are immunized in the first year of life. We do not think that avoiding vaccination, as a potential trigger, would prevent onset of this devastating disorder in patients who already harbour the SCN1A mutation."
In evaluating Dr. Kinsbourne's testimony and qualifications, the special master expressed concern "regarding Dr. Kinsbourne's reliability as an expert witness" due to the fact that Dr. Kinsbourne "has not maintained a hospi- tal based clinical pediatric neurology practice since 1981." The special master noted that Dr. Kinsbourne's testimony "reflected his lack of recent clinical practice," and that "[h]is testimony was highly generalized and lacked any grounding in practice." He also noted that "Dr. Kins-bourne does not publish, research, teach, counsel, attend meetings or conferences, or have any special training in the field of genetics." The special master concluded that "[t]he fact that for the past twenty-five years Dr. Kins-bourne has not focused his practice, research, or teaching in the field of seizure disorders, and that Dr. Kinsbourne has no expertise in the field of genetics significantly limited his ability to offer reliable, persuasive, and cogent testimony in this case." Although the special master encouraged the petitioners to submit expert testimony from a geneticist, they declined to do so and relied solely on Dr. Kinsbourne.
Three experts testified for the respondent. In Amelia Stone's case, Dr. Michael Kohrman and Dr. Gerald Raymond testified for the respondent. In Rachel Hammitt's case, Dr. Max Wiznitzer and Dr. Raymond testified for the respondent. The special master found the testimony of each of those witnesses to be helpful, but was particularly persuaded by Dr. Raymond, who has a background in both pediatric neurology and genetics. In his opinions in both cases, the special master stated: "Dr. Raymond's knowledge and experience with neurology and clinical genetics is extensive. His essentially unrebutted testimony was very persuasive and was relied upon heavily in deciding this case."
Dr. Raymond testified that the SCN1A gene mutation was the sole cause of SMEI in both Amelia and Rachel. He testified at length as to how he reached that conclusion, beginning with the fact that SMEI is highly corre- lated with a mutation in the SCN1A gene. All three of the respondent's experts further testified that there was no evidence that either Amelia or Rachel suffered brain damage as a result of their initial febrile seizures. The respondent's experts concluded that there was no evidence that the initial seizures contributed in any way to either child's SMEI.
Dr. Kinsbourne agreed that "SMEI has a genetic bas[is]" that is "very powerful," but he contended that "the pertussis vaccine caused fever, the fever triggered the seizure, [and] the seizure lasted a long time," thereby lowering each child's seizure threshold. As summarized by the special master in the Stone case, Dr. Kinsbourne's rebuttal essentially consisted of:
1) criticizing the testimony presented by Dr. Raymond regarding the factors a geneticist analyzes in determining a genotype-phenotype relationship; 2) arguing that the SCN1A gene mutation is not a reliable indicator of clinical outcome; 3) arguing that the scientific literature supports an environmental (vaccine role) in causation; 4) arguing that the vaccine was responsible for the first seizure, which was a complex febrile seizure, and complex febrile seizures damage the brain; 5) arguing that the [special master's] prior rulings in [two similar cases] require a finding on behalf of petitioners; and 6) criticizing Dr. Raymond's qualifications.
After considering all the evidence, the special master concluded that neither Amelia nor Rachel was entitled to compensation. He determined that the respondent had demonstrated by a preponderance of the evidence that the SCN1A gene mutation was "more likely than not the 'but for' and 'substantial factor' that caused" the SMEI in both children. Stone v. Sec'y of Health & Human Servs. (Stone I), No. 04-1041V (Fed. Cl. Spec. Mstr. Apr. 15, 2010); Hammitt v. Sec'y of Health & Human Servs. (Hammitt I), No. 07-170V (Fed. Cl. Spec. Mstr. Aug. 31, 2010).
The special master noted that the "issue that ultimately must be resolved is whether respondent demonstrated that the mutation is the substantial causal factor, or in other words that the vaccine did not also play a substantial causal role in [the children's] SMEI." Stone I at 48; Hammitt I at 50. As to that question, the special master wrote that "[t]here is simply no evidence that [either child's] initial seizure caused any brain damage, or somehow affected the expression of her genetic mutation in such a way that caused her to develop SMEI or experience further seizures." Stone I at 48; Hammitt I at 50. Dr. Kinsbourne, the special master found, "was unable to point to any evidence demonstrating that [either child's] vaccination acted as anything more than a trigger to her initial fever-induced seizure." Stone I at 48; Hammitt I at 50. He was "unable to point to any evidence that [either child's] initial febrile seizure caused her injury, which when combined with her mutation was a substantial cause of her SMEI." Stone I at 48; Hammitt I at 50. In Rachel's case, the special master stated that he found "compelling" Dr. Raymond's contrary testimony that based on the mutation in her SNC1A gene, she was "going to have [SMEI]," and that "[e]xcept for her having a seizure with fever," the DTaP vaccination "had no significant role in the development of her having [SMEI]." Hammitt I at 50. In Amelia's case, the special master stated that the evidence supported Dr. Raymond's opinion "that the initial fever-induced seizure was part of the normal progression of Amelia's SMEI," which was "completely unrelated to the fact that she had an immunization that day." Stone I at 48-49. Accordingly, the special master concluded that in both cases the petitioners had "failed to present evidence that the vaccine-induced seizure caused injury to [the child's] brain," and that the respondent had "met the burden of proving a factor unrelated to the vaccination caused [the children's] SMEI." Stone I at 51; Hammitt I at 53.
On review in the Court of Federal Claims, both reviewing judges remanded for further findings. The reviewing judge in the Hammitt case concluded that the special master had not specifically stated whether the petitioners had presented a prima facie case and, if so, whether the respondent had proved that the SCN1A gene mutation was the "sole substantial factor" in causing Rachel's SMEI. Hammitt v. Sec'y of Health & Human Servs., No. 07-170V (Fed. Cl. Dec. 22, 2010). The reviewing judge in the Stone case concluded that the special master had not made an express ...