ClinVar

In affected members of a family with Schnyder crystalline corneal dystrophy (SCCD; 121800) originally described by Battisti et al. (1998), Orr et al. (2007) identified heterozygosity for an A-to-G transition in the UBIAD1 gene, resulting in an asn102-to-ser (N102S) substitution. The mutation was not found in unaffected family members or in 144 Nova Scotian controls, 59 unrelated Caucasian CEPH HapMap DNA samples, or 89 unrelated Asian HapMap DNA samples.

In affected members of 5 unrelated Caucasian families with SCCD, 2 of which were previously reported as pedigrees '11' and '12' in a mapping analysis by Theendakara et al. (2004), Weiss et al. (2007) identified heterozygosity for the N102S substitution. Asn102 is evolutionarily conserved. Prediction of the protein structure indicated that a prenyltransferase domain and several transmembrane helices are affected by the mutation. The mutation was not found in any unaffected family members tested or in 200 control chromosomes.

In affected members from 5 families with SCCD, 2 of which were American, 1 Czechoslovakian, 1 Taiwanese, and 1 German (previously described as 'family I' by Lisch et al., 1986), Weiss et al. (2008) identified heterozygosity for the N102S mutation in exon 1 of the UBIAD1 gene. The mutation was not found in 200 chromosomes from 100 unrelated Caucasian DNA samples.

Nickerson et al. (2013) analyzed SCCD patient B-cell lysates and observed that the N102S mutant had significantly reduced biosynthetic activity, 22% lower than that of wildtype UBIAD1.