LMX1B gene mutation in a Saudi patient with bilateral symmetrical hypoplastic nails of the upper limbs

Nail-patella syndrome (NPS) is a rare autosomal dominant disorder that is highly penetrant with marked phonotypical variability among inter- and intra-familial cases. We describe here a patient with a characteristic phenotype of familial bilateral symmetrical hypoplastic nails of the upper limbs and a small patella displaced by ultrasound. This patient has a homozygous mutation in the gene encoding LIM homeobox transcription factor 1 beta (LMX1B). Molecular DNA sequencing revealed that this is the first report in the literature linking a homozygous c.268C>T (p.Phe90Leu) mutation located within the highly conserved LIM-A domain of the LMX1B gene with presentation of NPS. Familial molecular analysis showed that both parents are heterozygous for the c.268C>T mutation. Therefore, prenatal diagnosis and genetic counselling are important considerations for family future planning.