Novel homozygous mutation in DSP causing skin fragility-woolly hair syndrome: report of a large family and review of the desmoplakin-related phenotypes

Desmoplakin is an important cytoskeletal linker for the function of the desmosomes. Linking desmoplakin to certain types of cardiocutaneous syndromes has been a hot topic recently. Skin fragility-woolly hair syndrome is a rare autosomal recessive disorder involving the desmosomes and is caused by mutation in the desmoplakin gene (DSP). We report five members from a large family with skin fragility-woolly hair syndrome. The index is a 14-year-old girl with palmoplantar keratoderma, woolly hair, variable alopecia, dystrophic nails, and excessive blistering to trivial mechanical trauma. No cardiac symptoms were reported. Although formal cardiac examination was not feasible, the echocardiographic evaluation of the other two affected younger siblings was normal. Homozygosity mapping and linkage analysis revealed a high LOD score region in the short arm of chromosome 6 that harbors the DSP. Full sequencing of the DSP showed a novel homozygous c.7097 G>A (p.R2366H) mutation in all affected members, and the parents were heterozygous. This is the report of the third case/family of the skin fragility-woolly hair syndrome in the literature. We also present a clinical and molecular review of various desmoplakin-related phenotypes, with emphasis on onset of cardiomyopathy. The complexity of the desmoplakin and its variable presentations warrant introducing the term 'desmoplakinopathies' to describe all the phenotypes related to defects in the desmoplakin.