Moniletrix of the scalp from almost normal aspect to total alopecia: variable intrafamilial expressiveness

Abstract Monilethrix is a rare defect of the hair shaft, with most cases showing an autosomal dominant pattern of inheritance and variable clinical expression. It is characterized by hypotrichosis secondary to hair fragility. The diagnosis is made through trichoscopy, detecting typical findings such as periodic narrowing at regular intervals, giving the hair the appearance of beads in a rosary. This article reports the case of six members of a family diagnosed with monilethrix with alopecia of varying degrees.

Desmoglein 4 gene mutation analysis in a pedigree with autosomal recessive hereditary monilethrix / 中华皮肤科杂志

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.

Desmoglein 4 gene mutation analysis in a pedigree with autosomal recessive hereditary monilethrix / 中华皮肤科杂志

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 theabove 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.

Mutation analysis of the type Ⅱ hair keratin gene in a family of Han nationality with monilethrix / 中华皮肤科杂志

Objective To detect mutations of the type Ⅱ human basic hair keratin (hHb) gene in a family of Han nationality with monilethrix.Methods Clinical data were collected from a family of Han nationality with monilethrix.Dermoscopy was performed to observe hairs of the family members,and light microscopy and scanning electron microscopy (SEM) were conducted to investigate the features of lesional hairs.Blood samples were obtained from the proband,other family members and 100 healthy controls,and DNA was extracted from these blood samples.Polymerase chain reaction (PCR) was performed to amplify the exons 1 and 7 of the hHb1,hHb3 and hHb6 genes,and DNA sequencing results were compared with their sequences in the GenBank database.Results The proband was an 8-year-old girl,whose head hairs had become fragile and easy to pull out since 2 months after birth.Skin examination showed diffuse sparsehairs,most of which were 2-cm-long broken hairs with abnormal appearance.Moniliform hairs were scattered all over the head,especially on the occipital region,and follicular keratotic papules were observed on the back of the neck.The proband was diagnosed with monilethrix.There were a total of 15 members in the 3-generation family,and 4 were diagnosed with monilethrix.The hair shafts of the 4 patients all showed typical moniliform structures.After 9-month consecutive treatment with topical minoxidil 2％ solution,the hairs of the proband turned longer and denser.A heterozygous mutation c.1237G＞A (p.E413K) was identified in the exon 7 of the hHb6 gene in the 4 patients,but not in the other family members or 100 healthy controls.Conclusion The E413K mutation of the hHb6 gene was firstly found in the patients in a Chinese Han family with monilethrix,which may be responsible for moniliform hairs.

Description of clinical aspects and microscopy of the hair shaft of a carrier of familial monilethrix / Descrição dos aspectos clínicos e da microscopia da haste capilar de um portador de monilétrix familiar

ABSTRACT Monilethrix is a genetic condition that affects the hair shaft. We describe a family with this disease, focusing on its clinical aspects and microscopic hair characteristics. The patient was a 10-year-old female with history of hypotrichosis. In addition to diffuse alopecia, there was brittle hair, with ruptures in the hair shaft at different levels. The hair had a nodular appearance at naked eye. Other family members had the same symptoms, what indicates an autosomal dominant pattern of inheritance. Microscopic analysis revealed capillary fibers with areas of elliptical nodular appearance interspersed with regions of dystrophic constriction.

RESUMO A monilétrix é uma condição genética que acomete a haste capilar. Descrevemos uma família com essa doença, enfocando seus aspectos clínicos e as características microscópicas do cabelo. A paciente era do sexo feminino, 10 anos de idade, e apresentava história de hipotricose. Além da alopecia difusa, notava-se um cabelo quebradiço, com rupturas na haste capilar em diferentes níveis. Os cabelos possuíam um aspecto nodular a olho nu. Outros membros da família apresentavam os mesmos sintomas, o que indica um padrão de herança autossômica dominante. A análise microscópica revelou fibras capilares com áreas de aparência nodular elíptica, intercaladas por regiões de constrição distrófica.