| Atrichia with papular lesions is a rare,autosomal recessive disorder characterized clinically by the occurrence of universal congenital alopecia and disseminated papular lesions. Published estimates of the prevalence of this disorder remain surprisingly low considering pathogenetic mutations in HR have been found in distinct ethnicities around the world. Recently, HGMD has collected 12 types of mutations in HR, including missense mutation, nonsense mutation, splicing and small deletions. It has not yet been reported in china. Objective To identify the hairless gene mutations in a family of atrichia with papular lesions. Methods Biopsies were taken from a flesh-colored lesion on the neck and a red lesion on the forearm for histopathological examination. Blood samples were collected from the family. Genomic DNA was extracted from blood samples using standard method. Complete encoding sequences of hairless gene were detected by polymerase chain reaction (PCR) and DNA sequencing. Results Compound heterozygous mutations were identified in the patient: We identified a heterozygous G-to-A transition at nucleotide 1010 in exon 3 of HR leading to the conversion of a glycin residue to a aspartic acid residue at amino acid position 337 (G337D). And we found a heterozygous C-to-T transition at nucleotide 1491 in exon 4 of HR. It results in a substitution of a stop codon for a glutamic acid residue at amino acid position 478(Q498X).A missense mutation(G1010A) in exon 3 of HR was identified in the patient's father. A missense mutation(G1010A) in exon 3 of HR was also identified in the patient's younger brother. A nonsense mutation(C1491T) in exon 4 of HR was identified in the patient's mother. The DNA sequence of HR was normal in control individuals. Conclusions G337D and Q498X mutations in hairless gene were the cause of the phenotypes in the patient. |
