Project description:Mutations in LIPH cause of autosomal recessive woolly hair/hypotrichosis (ARWH), and the 2 missense mutations c.736T>A (p.Cys246Ser) and c.742C>A (p.His248Asn) are considered prevalent founder mutations for ARWH in the Japanese population. To reveal genotype/phenotype correlations in ARWH cases in Japan and the haplotypes in 14 Japanese patients from 14 unrelated Japanese families. 13 patients had woolly hair, and 1 patient had complete baldness since birth. An LIPH mutation search revealed homozygous c.736T>A mutations in 10 of the patients. Compound heterozygous c.736T>A and c.742C>A mutations were found in 3 of the patients, and homozygous c.742C>A mutation in 1 patient. The phenotype of mild hypotrichosis with woolly hair was restricted to the patients with the homozygous c.736T>A mutation. The severe phenotype of complete baldness was seen in only 1 patient with homozygous c.742C>A. Haplotype analysis revealed that the alleles containing the LIPH c.736T>A mutation had a haplotype identical to that reported previously, although 4 alleles out of 5 chromosomes containing the LIPH c.742C>A mutation had a different haplotype from the previously reported founder allele. These alleles with c.742C>A are thought to be the third founder LIPH mutation causing ARWH. To accurately determine the prevalence of the founder mutations, we investigated allele frequencies of those mutations in 819 Japanese controls. Heterozygous c.736T>A mutations were found in 13 controls (allele frequency: 0.0079; carrier rate: 0.016), and heterozygous c.742C>A mutations were found in 2 controls (allele frequency: 0.0012; carrier rate: 0.0024). In conclusion, this study confirms the more accurate allele frequencies of the pathogenic founder mutations of LIPH and shows that there is a third founder mutation in Japan. In addition, the present findings suggest that the mutation patterns of LIPH might be associated with hypotrichosis severity in ARWH.
Project description:During the last decade, several causative genes for hereditary hair diseases have been identified, which have disclosed the molecular mechanisms involved in hair follicle morphogenesis and cycling. We and others recently reported that mutations in the P2RY5 gene, encoding an orphan G protein-coupled receptor, underlie autosomal recessive woolly hair (WH)/hypotrichosis. Although these findings clearly reveal the involvement of P2RY5 mutations in hereditary hair diseases, the clinical manifestations of P2RY5 mutations have not completely been elucidated because of limited information to date. In this study, we ascertained a consanguineous family of Iranian origin with an affected girl showing sparse and hypopigmented scalp hair. She exhibited the WH phenotype with normal hair density at birth, but progressed with age to develop hypotrichosis. Direct sequencing analysis resulted in the identification of a novel homozygous mutation in the P2RY5 gene of the patient, which results in a non-conservative amino acid change, G146R, at the protein level. Our findings extend the mutation spectrum of P2RY5 mutations, and further support a crucial role of P2Y5 in hair growth in humans.
Project description:Autosomal recessive hypotrichosis simplex with woolly hair is a rare dermatological disorder, characterized by sparse hair and tightly curled hair. We report on a new family affected with this disorder which has not previously been reported. In this family, 2 siblings were affected. We believe that the disorder is not rare, but is possibly misdiagnosed, and hence underreported.
Project description:Autosomal-recessive woolly hair (ARWH)/hypotrichosis is a hereditary hair disorder which is characterized by tightly curled hair and is associated with sparse hair. ARWH can be caused by mutations in the P2RY5 or lipase H (LIPH) gene. Disruption of either gene results in phenotypes with features of both wooly hair (WH) and hypotrichosis. In this study, we identified two Guyanese families with ARWH. Both families are of recent Indian descent. Mutation analysis resulted in the identification of mutations in the LIPH gene in both families. Affected individuals in the first family carry compound heterozygous mutations Ex7_8del and 1303_1309dupGAAAACG in the LIPH gene, while those in the second family have a homozygous mutation 659_660delTA in the LIPH gene. The mutations Ex7_8del and 659_660delTA were identified earlier in several Pakistani families with ARWH. Haplotype analysis using microsatellite markers close to the LIPH gene defined a founder haplotype shared in families from Pakistan and Guyana. Proteomic analysis of hair shaft samples from one of the families revealed no substantial changes among the proteins identified, indicating that the syndrome does not involve global alterations in protein expression. Our results further suggest a crucial role of LIPH gene in hair growth.
Project description:Mutations in the lipase member H (LIPH) gene cause autosomal recessive hypotrichosis with woolly hair. We report herein on five consanguineous families from Pakistan segregating hypotrichosis and woolly hair. Genetic investigation using polymorphic microsatellite markers revealed homozygosity for a region spanning the HYPT7 locus on chromosome 3 in affected individuals of all five families. Sequence analysis of the LIPH gene revealed a novel nonsense mutation (p.Arg260X) associated with hypotrichosis without woolly hair in one family. In the remaining four families we identified previously described mutations in a homozygous state in affected members. These findings extend the spectrum of known LIPH mutations in the Pakistani population.
Project description:Woolly hair (WH) belongs to a family of disorders characterized by hair shaft anomalies that clinically presents with tightly curled hair, which can be divided into syndromic and non-syndromic forms of WH. We have recently identified mutations in both LPAR6/P2RY5 and LIPH that are associated with autosomal recessive woolly hair (ARWH).To study the underlying genetic causes of autosomal woolly hair in Pakistani population.We studied 10 Pakistani families with ARWH for mutations in LPAR6/P2RY5 and LIPH and then performed haplotype analysis to confirm their segregation in the families.We identified five mutations in LPAR6/P2RY5, among which three were recurrent and two were novel in eight Pakistani families. We then showed that two of the mutations in LPAR6/P2RY5 are founder mutations in Pakistani families. Moreover, we identified two recurrent mutations in the LIPH gene in two Pakistani families.Our study extends the spectrum of mutations in LPAR6/P2RY5 gene and underscores those mutations in LPAR6/P2RY5 and LIPH result in similar phenotypes.
Project description:Autosomal recessive woolly hair/hypotrichosis (ARWH/H) is a nonsyndromic hair abnormality characterized by sparse, short and curly hair (WH/H). We report the case of a 3-year-old female, with no consanguineous ancestry, who exhibited WH/H. Normal hair was observed at birth, but severe hair loss had developed within the first 6 months; however, her hair density had improved somewhat by age 3. Light microscopy showed hair shaft invaginations, and polarized light microscopy suggested complete medullary disruption of the hair. Direct sequence analysis of peripheral blood showed a homozygous missense mutation in exon 6 of the lipase H gene (LIPH: c.736T>A, p.Cys246Ser), and the exact same mutation was found in the heterozygous state in both parents. The initial deterioration followed by improvement with age observed in this case suggests that the clinical course of ARWH/H may vary among patients with the same mutation in LIPH detected in this case, indicating that additional factors may influence the effect of LIPH on hair development.
Project description:Pure hair and nail ectodermal dysplasia (PHNED) comprises a heterogeneous group of rare heritable disorders characterized by brittle hair, hypotrichosis, onychodystrophy and micronychia. Autosomal recessive (AR) PHNED has previously been associated with mutations in either KRT85 or HOXC13 on chromosome 12p11.1-q14.3. We investigated a consanguineous Pakistani family with AR PHNED linked to the keratin gene cluster on 12p11.1 but without detectable mutations in KRT85 and HOXC13. Whole exome sequencing of affected individuals revealed homozygosity for a rare c.821T>C variant (p.Phe274Ser) in the KRT74 gene that segregates AR PHNED in the family. The transition alters the highly conserved Phe274 residue in the coil 1B domain required for long-range dimerization of keratins, suggesting that the mutation compromises the stability of intermediate filaments. Immunohistochemical (IHC) analyses confirmed a strong keratin-74 expression in the nail matrix, the nail bed and the hyponychium of mouse distal digits, as well as in normal human hair follicles. Furthermore, hair follicles and epidermis of an affected family member stained negative for Keratin-74 suggesting a loss of function mechanism mediated by the Phe274Ser substitution. Our observations show for the first time that homozygosity for a KRT74 missense variant may be associated with AR PHNED. Heterozygous KRT74 mutations have previously been associated with autosomal dominant woolly hair/hypotrichosis simplex (ADWH). Thus, our findings expand the phenotypic spectrum associated with KRT74 mutations and imply that a subtype of AR PHNED is allelic with ADWH.
Project description:Autosomal recessive woolly hair/hypotrichosis (ARWH/H) is a rare nonsyndromic hair abnormality characterized by sparse, short, and curly hair. we report a case of a 5-year-old girl from consanguineous parents, who presented with ARWH/H since birth. Dermoscopic findings showed thin sparse hair. Genetic testing showed homozygous mutation in the LPAR6 gene.
Project description:Hypotrichosis simplex (HS) with and without woolly hair (WH) comprises a group of rare, monogenic disorders of hair loss. Patients present with a diffuse loss of scalp and/or body hair, which usually begins in early childhood and progresses into adulthood. Some of the patients also show hair that is tightly curled. Approximately 10 genes for autosomal recessive and autosomal dominant forms of HS have been identified in the last decade, among them five genes for the dominant form. We collected blood and buccal samples from 17 individuals of a large British family with HS and WH. After having sequenced all known dominant genes for HS in this family without the identification of any disease causing mutation, we performed a genome-wide scan, using the HumanLinkage-24 BeadChip, followed by a classical linkage analysis; and whole exome-sequencing (WES). Evidence for linkage was found for a region on chromosome 4q35.1-q35.2 with a maximum LOD score of 3.61. WES led to the identification of a mutation in the gene SORBS2, encoding sorbin and SH3 domain containing 2. Unfortunately, we could not find an additional mutation in any other patient/family with HS; and in cell culture, we could not observe any difference between cloned wildtype and mutant SORBS2 using western blotting and immunofluorescence analyses. Therefore, at present, SORBS2 cannot be considered a definite disease gene for this phenotype. However, the locus on chromosome 4q is a robust and novel finding for hypotrichosis with woolly hair. Further fine mapping and sequencing efforts are therefore warranted in order to confirm SORBS2 as a plausible HS disease gene.