RESUMO
Pili multigemini is an uncommon hair follicle disorder, where multiple hair shafts emerge from the same follicular opening. While it is commonly observed in men's facial hair, it has also been reported, albeit infrequently, in other areas of the body. Here we describe an unusual case of congenital pili multigemini presenting on the eyebrow of a female infant.
RESUMO
Pili multigemini is defined as the presence of two or more hair shafts in one hair follicle. It has mostly been reported to occur in the beard of men; however, it has been reported to occur uncommonly at other locations of the body as well. We present a rare case of a patient who presented with folliculitis on the abdomen which was incidentally detected as pili multigemini.
RESUMO
Investigations of hereditary phenotypes in spontaneous mutants may help to better understand the physiological functions of the altered genes. We investigated two unrelated domestic shorthair cats with bulbous swellings of the hair shafts. The clinical, histopathological, and ultrastructural features were similar to those in mice with lanceolate hair phenotype caused by loss-of-function variants in Dsg4 encoding desmoglein 4. We sequenced the genomes from both affected cats and compared the data of each affected cat to 61 control genomes. A search for private homozygous variants in the DSG4 candidate gene revealed independent frameshift variants in each case, c.76del or p.Ile26fsLeu*4 in case no. 1 and c.1777del or p.His593Thrfs*23 in case no. 2. DSG4 is a transmembrane glycoprotein located primarily in the extracellular part of desmosomes, a complex of adhesion molecules responsible for connecting the keratin intermediate filaments of neighbouring epithelial cells. Desmosomes are essential for normal hair shaft formation. Both identified DSG4 variants in the affected cats lead to premature stop codons and truncate major parts of the open-reading frame. We assume that this leads to a complete loss of DSG4 function, resulting in an incorrect formation of the desmosomes and causing the development of defective hair shafts. Together with the knowledge on the effects of DSG4 variants in other species, our data suggest that the identified DSG4 variants cause the hair shaft dystrophy. To the best of our knowledge, this study represents the first report of pathogenic DSG4 variants in domestic animals.
Assuntos
Doenças do Gato/genética , Desmogleínas/genética , Doenças do Cabelo/genética , Alopecia/genética , Alopecia/patologia , Alopecia/veterinária , Pelo Animal/patologia , Animais , Sequência de Bases , Estudos de Casos e Controles , Doenças do Gato/patologia , Gatos/genética , Códon sem Sentido , Mutação da Fase de Leitura , Doenças do Cabelo/patologia , Doenças do Cabelo/veterinária , Folículo Piloso/patologia , Homozigoto , Pele/patologia , Sequenciamento Completo do GenomaRESUMO
Pili multigemini is a rare disorder where more than one hair exists in a single hair follicle. Papillar tips that divide into several tips will produce several hair shafts, so that characteristically do not fuse again. This disorder is relatively frequent on the beard of adult men and on the scalp of children. However, extensive areas of pili multigemini in other locations have rarely been described.