Abstract: 【Abstract】 A 3-year-old female proband presented with patchy follicular keratotic papules on the hairless scalp after birth. At about the age of 2 years, sparse hairs of non-uniform thickness began to grow, but they fell out intermittently and were broken easily. Some eyebrows and eyelashes of different lengths fell out or were broken. Physical examination revealed good condition of nutrition, normal height, weight and intelligence, with no obvious abnormalities in other systems. Skin examination showed sparse and broken hairs with follicular keratotic papules on the vertex and occiput. Teeth, nails, toenails and sweat glands were normal. Dermoscopy, optical microscopy and scanning electron microscopy all showed that affected hairs gave a beaded appearance. Gene sequencing showed that the proband carried heterozygous deletions of exons 2 - 16 in the desmoglein 4 （DSG4） gene, and a heterozygous mutation c.574T>C（p.S192p）（NM-177986） in the DSG4 gene, which were inherited from her father and mother respectively. None of the above mutations in the DSG4 gene were found in 100 healthy controls. According to the gene sequencing results and clinical phenotype, the patient was finally diagnosed with autosomal recessive hereditary monilethrix, and the c.574T＞C mutation and heterozygous deletions of exons 2 - 16 of the DSG4 gene may contribute to autosomal recessive hereditary monilethrix in the child.

Key words: Monilethrix, DNA mutational analysis, Desmogleins, Autosomal recessive