ClinVar

In a French family segregating monilethrix (158000), Winter et al. (1998) found a lysine substitution of another highly conserved glutamic acid residue, glu402, in the EIATYRRLLEGEE motif of HB1. Family members bearing the glu402-to-lys mutation exhibited a particularly variable disease phenotype. Affected members included 2 infants, 1 with pronounced dystrophic alopecia, follicular keratosis, and clear-cut moniliform hair, and 1 with no hair loss at all and moniliform hair detectable only by electron microscopy. There was also an adult individual without any clinically or electron microscopically detectable signs, but with clear historical proof of the disease. Analysis of 'archival hairs' removed during childhood clearly demonstrated the beaded hair type. Winter et al. (1998) believed that this was the first demonstration of a moniliform hair phenotype in childhood with improvement thereafter, becoming unidentifiable at a later age.