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The Journal of Investigative Dermatology Aug 1990The plucked hairs and biopsied hair follicles of the scalp were obtained from a female patient with monilethrix. By scanning electron microscopy, the plucked hairs...
The plucked hairs and biopsied hair follicles of the scalp were obtained from a female patient with monilethrix. By scanning electron microscopy, the plucked hairs showed a typical moniliform feature composed of alternated nodes and internodes. By computer stereography, reconstructed three-dimensional models of in vivo hair structures showed that the diameter of hair shaft was partially reduced in the keratogenous zone and that the reduction was severe in the hair cortex and cuticle layers but mild in the inner root sheath. By transmission electron microscopy, a significant degeneration of hair matrix cells was found, and a zig-zag disarray of cortical tonofibrils and invaginations of the hair cuticle cells into the cortex were noticed in the suprabulbar portion. In some hairs, the hair bulbs showed no degeneration, but a degeneration of cortical cells and invaginations of hair cuticle were seen in some portions in the developing zone of the cortex. This suggests that not every hair matrix is damaged in a synchronized fashion, but individual hairs are affected independently. Furthermore, in all the hair and hair follicles examined, cytoplasmic vacuolations were always seen in the various layers, and abnormal formation of tonofibrils was often observed in the cortex. In monilethrix, a cell abnormality may inherently be present in the hair tissue and, when such abnormality occurs severely, the cortical cells are particularly affected in the hair matrix. This seems to result in a decrease in number of cortical cells and thinning of the hair shaft.
Topics: Child, Preschool; Computers; Female; Hair; Hair Diseases; Humans; Microscopy, Electron; Microscopy, Electron, Scanning; Models, Structural
PubMed: 2380577
DOI: 10.1111/1523-1747.ep12477967 -
Journal of Biomedical Research Jan 2011Monilethrix, a congenital disease of hair, is usually associated with mutations in keratin genes, like KRT81, KRT83 and KRT86. We conducted this study to investigate the...
Monilethrix, a congenital disease of hair, is usually associated with mutations in keratin genes, like KRT81, KRT83 and KRT86. We conducted this study to investigate the mutation of type II human basic hair keratin hHb/KRT gene in a Han family with monilethrix and obtain information for potential pathogenic mechanism study of monilethrix. Peripheral blood samples were drawn for genomic DNA detection. Exon 1 and exon 7 of the KRT81, KRT83 and KRT86 genes were amplified by PCR. All PCR products were sequenced directly using an ABI 310 DNA sequencer. These sequences were aligned with the standard sequences in GenBank using the BLAST software. PCR products were digested with restriction endonuclease and restriction fragment length polymorphism (RFLP) analysis was performed. In this study, we identified one novel mutation, which is a heterozygous transitional mutation of G→A at position 1,289 in exon 7 of the KRT86 gene [R430Q (KRT86)]. RFLP assays for the novel mutation excluded the possibility of polymorphism. The R430Q mutation of the KRT86 gene may be pathogenic for monilethrix. Meanwhile, we did not find any novel mutation or recurrent mutation in exons 1 and 7 of KRT81 and KRT83 and exon 1 of KRT86. There is a potential pathogenic gene in the subjects and our results expand the spectrum of mutations in the hHb6 gene.
PubMed: 23554671
DOI: 10.1016/S1674-8301(11)60006-7 -
The Journal of Investigative Dermatology Aug 1999Monilethrix, a rare human hair disorder with autosomal dominant transmission, can be caused by mutations in hair keratins. Up to now, causative mutations have only been...
Monilethrix: a novel mutation (Glu402Lys) in the helix termination motif and the first causative mutation (Asn114Asp) in the helix initiation motif of the type II hair keratin hHb6.
Monilethrix, a rare human hair disorder with autosomal dominant transmission, can be caused by mutations in hair keratins. Up to now, causative mutations have only been found in two type II cortex keratins, hHb6 and hHb1. In these hair keratins, the helix termination motif, HTM, was the only site in which mutations were located. The most frequent mutation, which has been found in 22 cases, was a Glu413Lys substitution in hHb6, whereas other mutations, i.e., hHb6 Glu413Asp, hHb1 Glu413Lys, and hHb1 Glu402Lys, have been reported in a distinctly lower number of cases. In this study, we describe the equivalent of the hHb1 Glu402Lys mutation in the HTM of cortex keratin hHb6. The mutation occurred in an American family in which it could only be detected in one clinically affected individual. Thus the underlying G-->A transition represents a spontaneous germ-line mutation in the hHb6 gene. This new mutation indicates that both the hHb6/hHb1 Glu413Lys substitution and the hHb6/hHb1 Glu402Lys substitution, represent mutational hotspots in the HTM of type II cortex keratins. However, we also describe a monilethrix-causing mutation in the helix initiation motif, HIM, of the cortex keratin hHb6. The critical Asn114Asp substitution was only found in affected members of a large Swedish three-generation family. Considering that since childhood, half of the affected individuals suffer from complete baldness and follicular keratosis, the new HIM mutation seems to be associated with a rather severe disease phenotype. In conclusion, our data strongly suggest that monilethrix is a disease of the hair cortex, whose etiology is interesting in that causative mutations seem to be restricted to type II hair keratins.
Topics: Amino Acid Sequence; Animals; Base Sequence; Female; Hair Diseases; Helix-Turn-Helix Motifs; Humans; Keratins; Male; Pedigree; Point Mutation
PubMed: 10469314
DOI: 10.1046/j.1523-1747.1999.00685.x -
International Journal of Trichology 2017
PubMed: 28839397
DOI: 10.4103/ijt.ijt_72_16 -
The Journal of Investigative Dermatology Jun 2006Monilethrix is a structural defect of the hair shaft usually inherited in an autosomal dominant fashion and caused by mutations in the hHb1, hHb3, and hHb6 keratin...
Monilethrix is a structural defect of the hair shaft usually inherited in an autosomal dominant fashion and caused by mutations in the hHb1, hHb3, and hHb6 keratin genes. Autosomal recessive inheritance in this disease has been sporadically reported. We encountered 12 Jewish families from Iraq, Iran, and Morocco with microscopic findings of monilethrix, but with no evidence of vertical transmission. Since no mutations were found in these three hair keratin genes, we examined nine chromosomal regions containing gene clusters encoding skin and hair genes. On chromosome 18q, a common haplotype in the homozygous state was found among all seven Iraqi patients, but not in 20 controls (P<0.0001). Sequencing of the main candidate gene from this region revealed four different mutations in desmoglein 4 (DSG4). Mutations in DSG4 have been previously reported in localized autosomal recessive hypotrichosis, a disorder that shares the clinical features of monilethrix but lacks the characteristic microscopic appearance of the hair shaft. Our findings have important implications for genetic counseling to monilethrix patients and families, and suggest that DSG4-associated hair disorders may be more common than previously thought.
Topics: Chromosomes, Human, Pair 18; Desmogleins; Genetic Counseling; Hair; Hair Diseases; Haplotypes; Humans; Hypotrichosis; Infectious Disease Transmission, Vertical; Mutation; Pedigree
PubMed: 16575393
DOI: 10.1038/sj.jid.5700251 -
Indian Journal of Dermatology 2008
PubMed: 19882001
DOI: 10.4103/0019-5154.41660 -
Journal of Korean Medical Science Mar 1987We report the first case of Menkes' disease in Korea, occurring in a 1 1/2 year old boy with characteristic clinical, arteriographic and pathologic features. Postmortem...
We report the first case of Menkes' disease in Korea, occurring in a 1 1/2 year old boy with characteristic clinical, arteriographic and pathologic features. Postmortem examination revealed widespread neuronal destruction and abnormally tortuous and elongated large arteries including cerebral, visceral and limb vessels. Microscopically, many of the hairs formed were twisted (pili torti), of varying caliber (monilethrix), and fractured (trichorrhexis nodosa). In the radioactivated analysis of scalp hair, copper elements was not found. The abnormal vessels were characterized by fragmentation and disruption of the internal elastic lamina with intimal proliferation. The neuronal destruction was widespread in the cerebral gray matter and in the cerebellum, and there was associated gliosis. The changes in the cerebellum were particularly severe, with neuronal loss in the internal granular cell layer. Many Purkinje cells were lost, and the remainder showed unusual dendritic sprouts from the cell body and grotesque proliferation of dendritic tree. In other organs, mild chronic peribronchitis, and scattered foci of immature glomeruli in renal cortex were noted.
Topics: Angiography; Autopsy; Brain Diseases, Metabolic; Carotid Arteries; Copper; Hair; Humans; Infant; Male; Menkes Kinky Hair Syndrome; Postmortem Changes; Radionuclide Imaging; Scalp
PubMed: 3269246
DOI: 10.3346/jkms.1987.2.1.75 -
Anais Brasileiros de Dermatologia 2021Monilethrix is a rare defect of the hair shaft, with most cases showing an autosomal dominant pattern of inheritance and variable clinical expression. It is...
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.
Topics: Alopecia; Alopecia Areata; Hair; Hair Diseases; Humans; Scalp
PubMed: 34272078
DOI: 10.1016/j.abd.2020.07.019 -
Journal of Clinical Pathology Dec 2005Microscopic examination of scalp hair can provide important diagnostic information in a range of paediatric conditions. It is a non-invasive and cost effective...
BACKGROUND
Microscopic examination of scalp hair can provide important diagnostic information in a range of paediatric conditions. It is a non-invasive and cost effective investigation, which is not widely performed.
AIMS
To examine retrospectively the value of hair examination by light microscopy, including polarising microscopy, in a specialist paediatric pathology department during a 15 year period (1989-2004) and to describe the morphological abnormalities indicative of specific paediatric conditions.
METHODS
Three hundred and twenty two hair samples were submitted. Microscopic changes were analysed in the light of clinical information categorised as: (1) erythroderma, (2) neurological impairment, (3) immunological/haematological defect, (4) ectodermal dysplasia, (5) abnormal hair only, and (6) non-specific/absent clinical details.
RESULTS
Abnormalities were evident in 49% of the samples. In 25%, the changes were compatible with specific diagnoses including Menkes disease, Netherton's syndrome, trichothiodystrophy, Griscelli and Chediak-Higashi syndromes, monilethrix, uncombable hair, and loose anagen syndromes. In respect of the clinical presentation groups noted above, diagnostic changes were seen in 41%, 32%, 33%, 0%, 29%, and 0%, respectively.
CONCLUSIONS
Morphological light microscopic examination of scalp hair is an inexpensive, rapid, and non-invasive investigation, which can provide valuable diagnostic information in a range of paediatric conditions.
Topics: Adolescent; Adult; Age Distribution; Child; Child, Preschool; Ectodermal Dysplasia; Hair; Hair Diseases; Humans; Ichthyosiform Erythroderma, Congenital; Infant; Infant, Newborn; Menkes Kinky Hair Syndrome; Mutation; Photomicrography; Retrospective Studies; Scalp; Syndrome
PubMed: 16311350
DOI: 10.1136/jcp.2005.027581 -
Skin Appendage Disorders Feb 2019
PubMed: 30815452
DOI: 10.1159/000490774