  United States Court of Appeals
      for the Federal Circuit
                ______________________

 MADISON DERIBEAUX, a minor, by her parents
  and natural guardians, GUS DERIBEAUX, AND
            KIMBERLY BURSHIEM,
               Petitioners-Appellants,

                           v.

      SECRETARY OF HEALTH AND HUMAN
                  SERVICES,
              Respondent-Appellee.
             ______________________

                      2012-5127
                ______________________

    Appeal from the United States Court of Federal
Claims in No. 05-VV-306, Judge George W. Miller.
                 ______________________

                 Decided: June 7, 2013
                ______________________

   CLIFFORD J. SHOEMAKER, Shoemaker, Gentry &
Knickelbein, of Vienna, Virginia, argued for petitioners-
appellants.

   GLENN A. MACLEOD, Senior Trial Counsel, Torts
Branch, Civil Division, United States Department of
Justice, of Washington, DC, argued for respondent-
appellee. With him on the brief were STUART F. DELERY,
2     DERIBEAUX   v. SECRETARY OF HEALTH AND HUMAN SERVICES

Principal Deputy Assistant Attorney General, RUPA
BHATTACHARYYA, Director, VINCENT J. MATANOSKI, Depu-
ty Director, and GABRIELLE M. FIELDING, Assistant Direc-
tor.
                 ______________________

    Before LOURIE, CLEVENGER, and REYNA, Circuit Judges.
LOURIE, Circuit Judge.
     Petitioners Gus Deribeaux and Kimberly Burshiem,
on behalf of their daughter, Madison Deribeaux
(“Deribeaux”), appeal from the judgment of the United
States Court of Federal Claims affirming a special mas-
ter’s decision denying their claim for compensation under
the National Vaccine Injury Compensation Program for
injuries allegedly caused by the Diphtheria-Tetanus-
acellular Pertussis (“DTaP”) vaccine. Deribeaux ex rel.
Deribeaux v. Sec’y of Health & Human Servs., 105 Fed. Cl.
583 (2012). Because the special master did not apply an
incorrect legal standard and because her evaluation of the
case was not arbitrary, capricious, an abuse of discretion,
or otherwise not in accordance with the law, we affirm.
                        BACKGROUND
    Deribeaux was born on August 19, 2001, and received
the DTaP vaccination on March 28, 2002. The next day,
she was taken to the emergency room having suffered
from a prolonged seizure. She continued to seize, and her
temperature was later recorded as 103.6 degrees Fahren-
heit; but all other tests were reported normal and she did
not suffer any additional seizures during several subse-
quent days that she remained at the hospital. Deribeaux,
105 Fed. Cl. at 585. Deribeaux continued to experience
seizures throughout the following year, however, and she
was again admitted to the hospital in April 2003 with
recurrent convulsive episodes. Her discharge note from
that instance stated that she had a seizure disorder that
began two days after the DTaP vaccination, with subse-
DERIBEAUX   v. SECRETARY OF HEALTH AND HUMAN SERVICES    3
quent admission and treatment for atypical Kawasaki
disease (a rare, immune-mediated vasculitis); Deribeaux
continued to experience seizures through 2005. Id. at
585–86.
    In December 2005, genetic testing revealed that
Deribeaux had a DNA sequence variation in her SCN1A
gene, which was reportedly not inherited and arose spon-
taneously. Id. at 586. SCN1A mutations have been
associated with several epilepsy syndromes, including
Severe Myoclonic Epilepsy of Infancy (“SMEI”), also
known as Dravet’s Syndrome. Following genetic testing,
Deribeaux’s treating physicians consistently noted the
diagnosis of SMEI and SCN1A mutation in association
with her chronic seizures and developmental delays. Id.
    This case was brought under the National Childhood
Vaccine Injury Act of 1986, 42 U.S.C. §§ 300aa-1 to -34
(“Vaccine Act”), as amended, which created the National
Vaccine Injury Compensation Program through which
claimants can petition the Court of Federal Claims to
receive compensation for vaccine-related injuries or death.
On March 11, 2005, before Deribeaux’s genetic mutation
was discovered, a petition was filed alleging that the
administration of the DTaP vaccine was a substantial
cause of her seizure disorder and developmental delay.
Pursuant to 42 U.S.C. § 300aa-12(d), a hearing was held
before a special master on September 20, 2007.
    At that hearing, Deribeaux presented expert testimo-
ny that she had a reaction to the vaccine as a result of her
poor immune system, which triggered her initial seizure
and subsequent condition. Deribeaux, 105 Fed. Cl. at 587.
In contrast, the Secretary presented expert testimony
that Deribeaux’s condition could be explained completely
by Kawasaki disease or by enterovirus, that there was no
evidence that her initial seizure resulted in brain damage,
and that DTaP vaccination can cause febrile seizures but
not chronic seizure disorders in children. Id. None of the
4   DERIBEAUX   v. SECRETARY OF HEALTH AND HUMAN SERVICES
medical records of treating physicians who diagnosed
Deribeaux with SMEI were filed into the record prior to
the initial entitlement hearing and no evidence concern-
ing Deribeaux’s genetic mutation or her diagnosis of
SMEI was presented. The special master concluded that
Deribeaux had established causation and was entitled to
compensation, and therefore directed the parties to begin
the damages phase of the proceeding. Id.
    During the damages phase, Deribeaux produced new
medical records, including documentation of her genetic
mutation and diagnosis of SMEI, which her treating
physicians had noted was the cause of her neurological
disorder. Id. In light of that new evidence, the Secretary
moved to set aside the special master’s decision and to re-
open the issue of entitlement. The case was then trans-
ferred to a second special master, who determined that
the evidence presented at the hearing conducted by the
earlier special master was sufficient to set forth
Deribeaux’s prima facie case and therefore to shift the
burden of proof to the Secretary to establish alternative
causation. Id.
     A limited supplemental hearing was held on June 28,
2011, focused on whether the Secretary could rebut
Deribeaux’s prima facie case by showing that her disorder
was caused by her SCN1A gene mutation, a factor unre-
lated to vaccination, pursuant to 42 U.S.C. § 300aa-
13(a)(1)(A)–(B).    The Secretary acknowledged that a
vaccine-induced fever likely triggered Deribeaux’s first
febrile seizure because individuals with SMEI are prone
to suffer seizures in the context of any temperature eleva-
tion, and presented additional expert testimony showing
that the sole cause of Deribeaux’s neurological disorders
was her genetic mutation and that the vaccination neither
caused nor aggravated her condition. Deribeaux, 105 Fed.
Cl. at 587. The Secretary’s position was thus that the
course of Deribeaux’s disorder was not altered by her
initial seizure and that the disabilities caused by her
DERIBEAUX   v. SECRETARY OF HEALTH AND HUMAN SERVICES    5
genetic mutation would have been the same with or
without the vaccine-induced seizure. Deribeaux contend-
ed that, notwithstanding her genetic mutation and diag-
nosis of SMEI, it was the DTaP vaccination that caused
her condition by triggering an immune deficiency that led
to additional disorders, including the atypical Kawasaki
disease, and further neurological damage.
    After considering the record as a whole, the special
master determined that the Secretary had carried the
burden of demonstrating alternative causation by estab-
lishing that an unrelated factor, namely, genetic muta-
tion, caused Deribeaux’s seizures and other neurological
disorders, and concluded that SMEI provided a complete,
alternative explanation for Deribeaux’s condition. Id. at
588. Accordingly, the special master set aside the previ-
ous entitlement decision and dismissed Deribeaux’s claim.
Deribeaux timely moved for review of that decision by the
Court of Federal Claims.
    The Court of Federal Claims denied the motion for re-
view and affirmed the decision, holding that the special
master did not abuse her discretion or act arbitrarily,
capriciously, or contrary to law in determining that the
Secretary had met the burden of proving by a preponder-
ance of the evidence that a substantial factor unrelated to
the DTaP vaccine caused Deribeaux’s injury. Id. at 596.
In particular, the court held that the special master: (i)
applied the correct legal standard as set forth in Althen v.
Secretary of Health & Human Services, 418 F.3d 1274
(Fed. Cir. 2005), id. at 590; (ii) acted properly within her
discretion to rely on the testimonial evidence of experts
and to determine the persuasiveness of experts, id. at 593;
and (iii) did not err or act arbitrarily or capriciously in
determining that Deribeaux’s genetic mutation was the
sole substantial cause of her condition despite the fact
that the vaccine triggered her initial seizure, id. at 594–
95.
6   DERIBEAUX   v. SECRETARY OF HEALTH AND HUMAN SERVICES
   This appeal followed. We have jurisdiction under 28
U.S.C. § 1295(a)(3).
                       DISCUSSION
    We review without deference a ruling by the Court of
Federal Claims on a special master’s decision to grant or
to deny entitlement to compensation under the Vaccine
Act. Lampe v. HHS, 219 F.3d 1357, 1360 (Fed. Cir. 2000);
Hines v. HHS, 940 F.2d 1518, 1523–24 (Fed. Cir. 1991).
Accordingly, we “perform[] the same task as the Court of
Federal Claims and determine[] anew whether the special
master’s findings were arbitrary or capricious.” Lampe,
219 F.3d at 1360; see also Hines, 940 F.3d at 1524 (hold-
ing that we review without deference the Court of Federal
Claims’s “determination as to whether or not the special
master’s decision was arbitrary, capricious, an abuse of
discretion, or otherwise not in accordance with law”).
    Whether the special master applied the appropriate
standard of causation is a legal determination that we
review without deference under the “not in accordance
with law” standard. Munn v. HHS, 970 F.2d 863, 870–73
(Fed. Cir. 1992). We apply the arbitrary and capricious
standard when reviewing findings of fact, and review the
special master’s discretionary rulings for abuse of discre-
tion. Id. at 870 n.10. As we have noted:
    Congress assigned to a group of specialists, the
    Special Masters within the Court of Federal
    Claims, the unenviable job of sorting through
    these painful cases and, based upon their accumu-
    lated expertise in the field, judging the merits of
    the individual claims. The statute makes clear
    that, on review, the Court of Federal Claims is not
    to second guess the Special Masters [sic] fact-
    intensive conclusions; the standard of review is
    uniquely deferential for what is essentially a judi-
    cial process. Our cases make clear that, on our
    review . . . we remain equally deferential. That
DERIBEAUX   v. SECRETARY OF HEALTH AND HUMAN SERVICES   7
   level of deference is especially apt in a case in
   which the medical evidence of causation is in dis-
   pute.
Hodges v. HHS, 9 F.3d 958, 961 (Fed. Cir. 1993) (internal
citations omitted).
    We have similarly held that “we do not sit to reweigh
the evidence. [If] the special master’s conclusion [is]
based on evidence in the record that [is] not wholly im-
plausible, we are compelled to uphold that finding as not
being arbitrary and capricious.” Lampe, 219 F.3d at 1363.
Thus, on review, we do “not reweigh the factual evidence,
assess whether the special master correctly evaluated the
evidence, or examine the probative value of the evidence
or the credibility of the witnesses—these are all matters
within the purview of the fact finder.” Porter/Knight v.
HHS, 663 F.3d 1242, 1249 (Fed. Cir. 2011).
    On appeal, Deribeaux contends that she has satisfied
the statutory requirements of the Vaccine Act in having
shown by a preponderance of the credible evidence that
her DTaP vaccination, not an unrelated factor, likely
caused her seizure disorder and subsequent developmen-
tal delays. Deribeaux argues that both the special master
and the Court of Federal Claims applied an evidentiary
standard not in accordance with law in finding that her
genetic mutation was the cause of her neurological condi-
tion by applying the Althen test to the Secretary’s burden
of proof, rather than the legal standard contained in the
Restatement (Second) of Torts, as announced in Shyface v.
HHS, 165 F.3d 1344 (Fed. Cir. 1999).
    The Secretary responds that the special master ap-
plied the correct evidentiary standard and stated a ra-
tional basis for the conclusion that Deribeaux’s genetic
abnormality caused both her susceptibility to a post-
vaccine seizure and her numerous subsequent seizures
and other neurological problems.
8   DERIBEAUX   v. SECRETARY OF HEALTH AND HUMAN SERVICES
    In this case, because Deribeaux’s injury is not listed
on the Vaccine Injury Table, she was required to prove
causation in fact by a preponderance of the evidence. See
42 U.S.C. § 300aa-13(a)(1)(A). In Althen, we established a
three-prong test that petitioners alleging an off-Table
injury must satisfy in order to prove causation. Specifi-
cally, a petitioner must
    show by preponderant evidence that the vaccina-
    tion brought about her injury by providing: (1) a
    medical theory causally connecting the vaccina-
    tion and the injury; (2) a logical sequence of cause
    and effect showing that the vaccination was the
    reason for the injury; and (3) a showing of a prox-
    imate temporal relationship between vaccination
    and injury.
Althen, 418 F.3d at 1278.
    To prove causation, a petitioner must show that the
vaccine was “not only a but-for cause of the injury but also
a substantial factor in bringing about the injury.”
Shyface, 165 F.3d at 1352–53.
     Once a petitioner establishes her prima facie case by
satisfying the Althen test, the burden then shifts to the
respondent to show by a preponderance of the evidence
that the injury is due to factors unrelated to the admin-
istration of the vaccine. 42 U.S.C. § 300aa-13(a)(1)(B). In
order to meet that burden, the respondent must “identi-
fy[] a particular . . . factor (or factors) and present[] suffi-
cient evidence to establish that it was the sole substantial
factor in bringing about the injury.” de Bazan v. Sec’y of
Health & Human Servs., 539 F.3d 1347, 1354 (Fed. Cir.
2008); accord Althen, 418 F.3d at 1278.
    As the Court of Federal Claims noted in this case, the
special master determined that the evidence presented at
the initial entitlement hearing, which did not include
evidence of Deribeaux’s genetic disorder, established a
DERIBEAUX   v. SECRETARY OF HEALTH AND HUMAN SERVICES      9
prima facie case of causation. See Deribeaux, 105 Fed. Cl.
at 589. Because the burden then shifted to the Secretary
to rebut the prima facie case, the special master accord-
ingly limited the proceedings before her to the specific
issue of whether the Secretary met the burden of estab-
lishing alternative causation. Id.
    Under the provisions of the Vaccine Act, it was in-
cumbent upon the special master to consider whether a
preponderance of the evidence demonstrated that
Deribeaux’s SCN1A genetic mutation was such an alter-
native cause once that evidence came to light. The Secre-
tary was “required not only to prove the existence of [a
factor unrelated], but also to prove by a preponderance of
the evidence that the [factor unrelated] actually caused”
the injury alleged. Knudsen v. HHS, 35 F.3d 543, 549
(Fed. Cir. 1994). Furthermore, the Secretary also had to
present sufficient evidence to prove that the alternative
factor was the sole substantial factor in bringing about
the injury. de Bazan, 539 F.3d at 1354.
    Based upon the record as a whole, including a balance
of all available expert testimony, medical evidence, and
test results, the special master determined that the
Secretary carried her burden and that the SCN1A gene
mutation was the sole substantial cause of Deribeaux’s
seizure disorder and developmental delays. Specifically,
the special master found that the evidence presented
supported: (i) an association between mutation of the
SCN1A gene, especially a missense mutation arising de
novo (i.e., not inherited) in a biologically conserved region,
as in this case, and SMEI; (ii) a logical sequence of cause
and effect between mutation of the SCN1A gene and
Deribeaux’s SMEI as corroborated by her genetic testing
and diagnoses of her treating physicians; (iii) a finding
that the time frame in which Deribeaux’s symptoms
developed was consistent with the diagnosis of SMEI,
which was not contradicted; and (iv) an analysis that the
SCN1A mutation was the sole substantial factor unrelat-
10   DERIBEAUX   v. SECRETARY OF HEALTH AND HUMAN SERVICES
ed to the DTaP vaccine in causing Deribeaux’s SMEI.
Deribeaux ex. rel. Deribeaux v. Sec’y of Health & Human
Servs., No. 05-306V, 2011 WL 6935594 (Fed. Cl. Dec. 9,
2011).
     The special master correctly identified that the Secre-
tary’s burden was to show a sequence of cause and effect
that is logical and legally probable, although causation by
the unrelated factor need not be established to a medical
or scientific certainty. See Deribeaux, 105 Fed. Cl. at 596;
see also Knudsen, 35 F.3d at 548–49 (“The determination
of causation in fact under the Vaccine Act involves ascer-
taining whether a sequence of cause and effect is ‘logical’
and legally probable, not medically or scientifically cer-
tain.”). Moreover, we have held that “the standards that
apply to a petitioner’s proof of actual causation in fact in
off-table cases should be the same as those that apply to
the government’s proof of alternative actual causation in
fact.” Knudsen, 35 F.3d at 549.
     Both the Court of Federal Claims and the special
master therefore applied the correct legal standards for
proving actual causation set forth in Althen to the Secre-
tary’s theory of alternative causation. As the Court of
Federal Claims correctly noted, “The Restatement stand-
ard, as adopted in Shyface, is not at odds with the Althen
factors; rather, those factors are themselves derived from
the Restatement standard.” Deribeaux, 105 Fed. Cl. at
589; see also Stone/Hammitt v. HHS, 676 F.3d 1373, 1379
(Fed. Cir. 2012) (“[T]he causation standard in off-Table
Vaccine Act cases is to be applied consistently with the
principles set forth in the Second Restatement of Torts.”
(citing Walther v. HHS, 485 F.3d 1146, 1151 (Fed. Cir.
2007)); Walther, 485 F.3d at 1150 (explaining that, in the
context of vaccine cases, Shyface “adopted the actual
causation standard of the Restatement (Second) of Torts”
and that “precedent has established that a petitioner
satisfies this standard by” meeting the three-part Althen
test).
DERIBEAUX   v. SECRETARY OF HEALTH AND HUMAN SERVICES 11
    In every case in which the Secretary asserts that an
unrelated factor caused the injury, there is necessarily an
allegation that a vaccine was the cause of the same injury.
Thus, the Vaccine Act requires the Secretary to establish
that the factor unrelated to the vaccination is the more
likely or principal cause of the injury alleged. Such a
showing establishes that the factor unrelated, not the
vaccination, was “principally responsible” for the injury.
See 42 U.S.C. § 300aa-13(a)(2)(B). In making this show-
ing, the Secretary refutes the prima facie finding that the
vaccination is both the “but for” cause and a “substantial
factor” in bringing about an alleged injury. Shyface, 165
F.3d at 1352; de Bazan, 539 F.3d at 1354 (stating that the
factor unrelated must be the “sole substantial factor” that
caused the injury). Because the factor unrelated must be
the “sole substantial factor,” the Secretary must establish
that the factor unrelated, not the vaccination, actually
caused the injury alleged. See de Bazan, 539 F.3d at
1354. The Secretary did so here.
    Accordingly, the special master did not act contrary to
law when she employed the Althen factors to analyze
whether, after Deribeaux established a prima facie case,
the Secretary carried her burden to prove that a factor
unrelated to the vaccine was the sole substantial cause of
Deribeaux’s injuries. We find no error in the special
master’s application of the preponderance standard under
the Vaccine Act and no basis to disturb her factual find-
ings as arbitrary or capricious in view of both the record
before us and the highly deferential standard of review
under which we must conduct such an evaluation.
                       CONCLUSION
    For the reasons stated above, the special master did
not apply an incorrect legal standard and her evaluation
of the case was not arbitrary, capricious, an abuse of
discretion, or otherwise not in accordance with the law.
Accordingly, the judgment is affirmed.
12   DERIBEAUX   v. SECRETARY OF HEALTH AND HUMAN SERVICES
                        AFFIRMED
