Case#: Hejtmancik_2008_Family_55001_Proband, sex and age not specified, family origin described as American of European ancestry
CasePresentingHPOs: Snowflake vitreoretinal degeneration HP:0011533, Corneal guttata HP:0012038, Presenile cataracts HP:0007819, Abnormal vitreous humor morphology HP:0004327, Retinal detachment HP:0000541
CaseHPOFreeText: All family members have been diagnosed with Snowflake vitreoretinal degeneration between the ages of 12 and 85 years of age. Please note that detailed phenotypes were found in PMID: 14644728, and included fibrillar vitreous degeneration.
CaseNotHPOs: N/A
CaseNotHPOFreeText: Orofacial features, early-onset hearing loss, and arthritis were absent.
CasePreviousTesting: The proband was previously subjected to linkage analysis mapping the causal locus to chromosome 2 (PMID: 15557460).
CaseMethod1: linkage analysis
CaseMethod2: Sanger sequencing of KCNJ13, COL4A3, SLC19A3, DNER, SLC17, 16A14, LOC646839, CAB39, PSMD1, ARMC9, NCL, PTMA, PDE6D, COPS7B, ECEL1, EFHD1, TNRC15, ATG16L1, SAG, USP40, and CENTG2
CaseGenotypingMethod: The family was previously genotyped by linkage analysis mapping the causal locus to chromosome 2 (PMID: 15557460), followed by Sanger sequencing of KCNJ13, COL4A3, SLC19A3, DNER, SLC17, 16A14, LOC646839, CAB39, PSMD1, ARMC9, NCL, PTMA, PDE6D, COPS7B, ECEL1, EFHD1, TNRC15, ATG16L1, SAG, USP40, and CENTG2.
Variant: The individual harbors the NM_002242.4(KCNJ13):c.484C>T (p.Arg162Trp) variant in the heterozygous state.
ClinVar: 6585
gnomAD: The variant is found in gnomAD version 4.1.0 at a frequency of 0.0000008536 (1 / 1,171,470) in the European (non-Finnish) population
https://gnomad.broadinstitute.org/variant/chr2-232768790-G-A?dataset=gnomad_r4
VariantEvidence:NM_002242.4(KCNJ13):c.484C>T (p.Arg162Trp) is a missense variant that has functional evidence of electrophysiological abnormalities and loss of sensitivity to different K+ concentrations, when exogenously expressed in CHO cells (Figure 2).
CaseAddInfo: The proband's family includes 12 other affected individuals carrying the variant, and 14 unaffected individuals (as well as 4 unaffected spouses) without the variant.
CasePMIDs: PMID: 15557460, PMID: 14644728