A familial case of nail patella syndrome with a heterozygous in-frame indel mutation in the LIM domain of LMX1B

Nail patella syndrome (NPS; MIM161200) involves the classical clinical tetrad of nail aplasia/hypoplasia, patellar aplasia/hypoplasia, elbow arthrodysplasia, and iliac horns [1,2]. Other body systems, such as the kidneys and eyes, are also involved [3]. NPS is an autosomal dominant disorder caused by heterozygous loss-of-function mutations in LIM homeobox transcription factor 1 beta (LMX1B) [4]. LMX1B is a member of the LIM-homeobox transcription factors and is comprised of one DNA-binding homeodomain and two protein-binding LIM domains, LIM-A and LIM-B domains [3].