Case#: Two affected sisters/Female siblings/Progressive onset initially presenting as Stargardt disease

DiseaseAssertion: ABCA4

FamilyInfo: Large American family pedigree with two affected sisters. Both sisters were compound heterozygous for two novel ABCA4 variants. Unaffected relatives carried one variant or neither variant, supporting autosomal recessive inheritance.

CasePresentingHPOs: HP:0000556, HP:0000572, HP:0007754, HP:0000648, HP:0000510, HP:0001133, HP:0000610

CaseHPOFreeText: Proband initially showed phenotype compatible with Stargardt disease with progressive central vision loss. Over several years disease advanced into severe cone-rod dystrophy with worsening retinal degeneration, abnormal visual fields, and reduced electroretinography responses.

CaseNotHPOs: n/a

CaseNotHPOFreeText: Unaffected family members with only one mutation had no retinal disease phenotype.

Genotyping Method: Genome-wide linkage analysis using 408 microsatellite markers followed by direct Sanger DNA sequencing of all ABCA4 exons and exon-intron boundaries. Segregation analysis performed in family members.

PreviouslyPublished: No, both variants were novel at time of publication.

Variant: ABCA4 (RefSeq: NM_000350.3): c.655A>T ; ABCA4 (RefSeq: NM_000350.3): c.5312+3A>T

ClinVar: 632118

CAID: n/a

SupplementalData: Variants absent in 200 unrelated controls. Clinical testing included visual acuity, fundus examination, fluorescein angiography, visual field testing, and electroretinography. Compound heterozygous state associated with severe progressive phenotype.