To date only one familiar (mother and daughter) and two sporadic cases have been described.
Sporadic case 1: de novo 1-bp deletion (196delC) in exon 3, causing a frameshift predicted to result in premature termination (Leu66CysfsTer48) of the protein.
Sporadic case 2: de novo A-G transition (41-2A-G) in intron 1, predicted to create a novel splice acceptor site 1 base before the wildtype splice site (Val14Glyfs*19).
Familiar case: heterozygous 55C>T transition in exon 2, resulting in a nonsense mutation (Q19X). The mutations are predicted to act with a loss of function mechanism. Molecular testing is available and recommended when the diagnosis is suspected. The diagnosis relies on sequencing of the coding regions. Dosage analysis of negative female cases should be taken into accounts to detect genomic rearrangements although none have been described to date. Differential diagnosis with LSDMCA1 and LSDMCA3 should also be considered in negative cases.
COX7B