A novel heterozygous missense variant in ribosomal protein L21 associated with familial hypotrichosis simplex

Hypotrichosis 12 (HYPT12) is an autosomal dominant, nonsyndromic hypotrichosis, caused by a pathogenic variant in the RPL21 gene encoding ribosomal protein L21, although only two pedigrees harbouring the amino acid substitution, p.Arg32Gln, have been reported previously. We present the case of a 44-year-old White British man with progressive hair loss since the age of 10 months, affecting his scalp, eyebrow, eyelashes and most of his body. Similar hair loss also affected several members of his family, with likely autosomal dominant inheritance. Using whole-exome sequencing, we identified a rare heterozygous missense variant (NM_000982.3:c.127A > G, NP_000973.2:p.Lys43Glu) in RPL21, and subsequent Sanger sequencing confirmed segregation of this variant in affected family members.

Automated summary

HYPT12 is an autosomal dominant, nonsyndromic hypotrichosis caused by a pathogenic variant in the RPL21 gene. We report a case of a 44-year-old White British man with progressive hair loss, and whole-exome sequencing identified a rare heterozygous missense variant in RPL21. This variant was confirmed to segregate in affected family members.