Case#: 14-year-old, female, asian (Chinese) patient

DiseaseAssertion: ABCA-4 associated retinal dystrophy

FamilyInfo: The effect of the deep intronic variant on splicing was validated by a minigene assay in our previous study (Tian et al., 2022). Co-segregation analysis result exhibited that the variant c.1222C>T p.(Arg408Ter) came from the female parent, and the deep intronic variant c.2919-884G>T p.[Phe973LeufsTer3,=] from the male parent

ParentalTesting: Co-segregation analysis result exhibited that the variant c.1222C>T p.(Arg408Ter) came from the female parent, and the deep intronic variant c.2919-884G>T p.[Phe973LeufsTer3,=] from the male parent

CasePresentingHPOs: HP:0000556

CasePhenotypeFreeText: ABCA4-associated retinal dystrophy

CaseNotHPOs: NR

CaseNotPhenotypeFreeText: NR

CasePreviousTesting:NR

GenotypingMethod:

In the present study, we recruited a 14-year-old female patient diagnosed with ABCA4-RD. Biallelic variants were found in this patient, including the nonsense variant c.1222C>T p.(Arg408Ter) detected by Sanger sequencing and the deep intronic variant c.2919-884G>T p.[Phe973LeufsTer3,=] identified by next-generation sequencing.

We isolated peripheral blood mononuclear cells (PBMCs) from the patient’s peripheral venous blood and introduced three episomal plasmids containing transcription factors OCT4, SOX2, NANOG, LIN28, c-MYC, KLF4, and SV40LT into PBMCs. The reprogramming iPSC line, named BIOi003-A, showed stabilized morphology (Fig. 1A) and a normal karyotype in culture (Fig. 1B). Then, the endogenous expression of two pluripotent biomarkers, POU5F1 and NANOG, was detected (Table 2). The expression levels were compared with human embryonic stem cell line H1(hESC-H1) and mesenchymal stem cell line P3 (MSC-P3) by qRT-PCR (Fig. 1C). Surface markers SSEA4 and TRA-1–81 were analyzed by flow cytometry (Fig. 1D). the ABCA4 compound heterozygous variants c.(1222C>T;2919-884G>T) p.[Arg408Ter;Phe973LeufsTer3,=] were verified by Sanger sequencing (Fig. 1E). Furthermore, the teratoma assay exhibited the differentiation capacity of this iPSC line in vivo (Fig. 1F). Short tandem repeats (STR) analysis exhibited that the PBMCs and the iPSC line came from the same patient. PCR proved negative for mycoplasma contamination

Variant: NM_000350.3(ABCA4):c.1222C>T (p.Arg408Ter) and NM_000350.3(ABCA4):c.2919G>T (p.Leu973Phe)

LegacyVariant: c.1222C>T (p.Arg408Ter) and c.2919G>T (p.Leu973Phe)

ClinVar: 99035 and NR

CAID: CA179692 and CA341275270

gnomeAD: 1:94544895 G / A and NR

MultipleGeneVariants: No

PreviouslyPublished:No

AdditionalInfo: One patient was homozygous at the ABCA-4 gene, so there is information about both variants in one annotation because there is only one patient.