Atrichia With Papular Lesions Research Articles

A rare cause of irrevocable childhood alopecia feigning alopecia universalis: Atrichia congenita with papular lesions

Atrichia congenita with papular lesions is rare, autosomal recessive condition that leads to complete hairloss which is irreversible and with keratin filled papular lesions. An insertion mutation in the exon 2 of hairless gene is responsible for the hairloss. Middle and lower portions of hair follicle are replaced by keratinizing cysts with absence of hair shafts. We here by reporting a case of 8-year-old girl with complete hairloss over scalp, eyebrows, eyelashes, and body which started at birth and complete hairloss was gradual by 9 months age on view of its rarity and misdiagnosis.

Papular atrichia

<p>Congenital atrichia or papular atrichia is a rare form of irreversible alopecia inherited autosomal recessively. Atrichia congenita with papular lesions represents a complex and heterogeneous group of genodermatoses characterized by irreversible complete hair loss soon after birth, and associated with the development of keratin-filled cysts over the body. Mutation of the human hairless (HR) gene on chromosome 8p22 has been implicated with this condition. It has broad differential diagnosis and poses diagnostic and therapeutic challenges. We report an 8 year girl presenting with complete loss of hair over scalp, eye brows, eye lashes, and body soon after birth with papular lesions over face.<strong></strong></p>

Identification of a recurrent nonsense mutation in HR gene responsible for atrichia with papular lesions in two Kashmiri families

Congenital atrichia (CA) is a rare form of irreversible alopecia with an autosomal recessive mode of inheritance. This form of hair loss is mainly associated with mutations in the human hairless (HR) gene located at chromosome 8p21.3. An additional unique feature atrichia with papular lesions (APL) comprises keratin-filled cysts known as papules. The present study aimed to uncover the underlying genetic causes of APL in two consanguineous Kashmiri families. In the present study, two consanguineous families of Kashmiri origin with APL displaying an autosomal recessive mode of inheritance were investigated. Whole exome and Sanger sequencing followed by bioinformatic studies, variant prioritization, Sanger validation and segregation analysis was performed to find the mutation. A recurrent nonsense (NM_005144: c.2818C > T:p.Arg940*) mutation was detected in exon 13 of the human HR gene. Whole exome sequencing analysis has widely been used in the screening of single gene disorders mutations, both in research and diagnostic laboratories. Sanger sequencing alone for genes such as HR becomes expensive and time consuming. Instead, it is recommended that a patient is to screen by whole exome sequencing and then special attention first focuses on known genes of the APL phenotype. This is helpful for intime diagnosis, being more efficient and economic. The results obtained in the present study may contribute to prenatal diagnosis, carrier secreening and the genetic counseling of families with the APL phenotype in Kashmiri poplution.

Congenital atrichia with papular lesions: a rare cause of irreversible childhood alopecia

Congenital atrichia with papular lesions (APL) is a disease characterized by the complete absence of hair from the whole body occurring within a few months of birth and the presence of papules distributed over the body. A 9-year-old boy presented with sparse hair over his body and with a history of losing his hair soon after birth. Multiple skin-colored papules were observed over the scalp. A biopsy from a papule showed keratinous cysts in the dermis and the absence of hair follicles. A diagnosis of congenital APL was made after vitamin D-dependent rickets was excluded. This case highlights congenital APL as a cause of total alopecia.

A case of papular atrichia with dextrocardia and situs inversus: Association or coincidence?

A case of papular atrichia with dextrocardia and situs inversus: Association or coincidence?

413 Epidermal dysplasia and hair defects in the disheveled hair and ears (LmnaDhe) mouse

412 Hairless (Hr) mutations and phenotypes: The new and the old J Cook, CH Pratt, D Bikle, RH Rice, MV Wiles and JP Sundberg 1 The Jackson Laboratory, Bar Harbor, ME, 2 Environmental Toxicology, University of California, Davis, CA and 3 Dermatology and Medicine, University of California, San Francisco, CA Hairless mice were first described over 150 years ago in the form of the severe rhino mouse mutation (Hr) closely followed by a more mild phenotypic allele named hairless (Hr). Eventually both these alleles were established in both inbred and outbred mouse colonies. About 30 years ago these mice, primarily the hairless allele as it was called with the milder phenotype, became commonly used for skin cancer research, both UV light and chemical carcinogen induced, as the mice lacked hair as adults and were considered by many to be useful models of normal human skin. Subsequently, it was found that the Hr was a good model of papular atrichia. Today, there is a rich, but possibly confusing, landscape of different mutantHr alleles present on a multitude of inbred, outbred, congenic, and segregating mouse strains. To confound this problem further there are also a number of mutant Hr phenocopies, i.e. mouse strains with mutations in genes that mimic the hairless phenotype, such as mutant alleles in the Vdr, Odc1, and other genes in the putrescine pathway. In this overview, we will clarify the phenotypes, genotypes, and mouse strain considerations that need to be accounted for when designing a study and interpreting the results of studies using these mice including many new alleles, both spontaneous and genetically engineered. 413 Epidermal dysplasia and hair defects in the disheveled hair and ears (Lmna) mouse CH Pratt, J Cook and JP Sundberg The Jackson Laboratory, Bar Harbor, ME Lamin A is one component of the nuclear lamina, a chromatin-binding network of type V intermediate filaments, including Lamin C, B1 and B2 which together form a proteinaceous boundary to the nucleus. The Lmna/LMNA gene has over 200 known miss-sense mutations that cause a range of disease phenotypes including progeria, muscular dystrophy, lipodystrophy, and cardiomyopathy. Human patients with mutations in the LMNA gene have a variety of skin abnormalities as does the semi-dominant, spontaneous mutation in the mouse called Disheveled hair and ears (Lmna). Ten day old Lmna/Lmna mice present with a markedly thickened dysplastic epidermis with scattered interfollicular pigmentation, multinucleated kertinocytes, and dystrophic hair follicles when compared to control littermates. The dysplastic epidermis aberrantly expressed mouse specific keratin 6, a nonspecific marker of hyperplasia and neoplasia, associated with downregulation of keratins 1 and 10. The stratum granulosum was thickened with increased expression of filaggrin and loricrin. Expression patterns were normal in wild type and heterozygous mice. Scanning electron microscopy and energy-dispersive X-ray spectroscopy revealed defects in hair shafts associated with low sulfur content of hair in Lmna/Lmna but not in +/+ or +/ Lmna mice. The Lmna mutation in mice causes marked epidermal dysplasia suggesting that mutations in Lmna may play an important role in cutaneous squamous cell carcinoma and possibly other types of skin cancer.

Disease causing homozygous variants in the human hairless gene.

Atrichia with papular lesions (APL) is a rare irreversible form of complete hair loss inherited in autosomal recessive manner. Hair loss is often followed by the appearance of multiple keratin-filled cysts or papules on exterior parts of the body. This phenotype results due to mutations in the human hairless gene (HR) mapped on chromosome 8p21.3. The present study was aimed to search for disease-causing sequence variants in the HR gene in five consanguineous families exhibiting features of APL. Linkage in five Pakistani lineal consanguineous families, displaying features of APL, was tested using microsatellite markers flanking the HR gene on chromosome 8p21.3. After constructing the haplotypes, variants in the gene HR were searched by dideoxy-chain termination sequencing. Haplotype analysis established linkage in all five families to the HR gene located on chromosome 8p.21.3. Subsequently, sequencing HR identified a novel homozygous nonsense variant (c.2541G>A, p.Trp847*) in one and previously reported two pathogenic variants (p.Cys690*, p.Pro1157Arg) in the other four families. Mutations identified extend the spectrum of mutations in the HR gene resulting in APL. Characterizing the clinical spectrum resulting from the disease-causing homozygous variants in the HR gene will direct clinical care of the family members.

Congenital atrichia with papular lesions

Congenital alopecia has broad differential diagnosis and poses diagnostic and therapeutic challenges. It is a rare form of irreversible alopecia inherited autosomal recessively. Atrichia congenita with papular lesions represents a complex and heterogeneous group of genodermatoses characterized by irreversible complete hair loss soon after birth, and associated with the development of keratin-filled cysts over the body. We report a case of 4-year-old boy presenting with complete loss of hair over scalp, eye brows, eye lashes, and body since birth. Patient also had papular lesions over body.

Atrichia with Papular Lesions in a Chinese Family Caused by Novel Compound Heterozygous Mutations and Literature Review

Background: Congenital atrichia with papular lesions (APL) is characterized by complete absence of body hair shortly after birth, along with papules, and caused by mutations in the hairless gene (HR). Objective: To investigate whether APL with HR mutations might also be found among patients in non-consanguineous Chinese families and to discuss the phenotypic variations with the same mutations. Methods: DNA sequencing of the HR was performed in the Chinese pedigree and in 100 controls. Results: A nonsense mutation c.T2265A in the patient and his father as well as a 2bp deletion (3482delCT) in the patient and his mother were detected. Conclusion: Our study identified the first mutation in exon 10 in HR as well as the second novel compound heterozygous mutations in a Chinese family, also adding new variants to the knowledge of HR mutations in APL. Phenotypic heterogeneity in congenital atrichia might be subject to the founder genes or modifier genes.

English

Atrichia with papular lesion is a rare disorder of hair development characterized by almost complete loss of scalp and body hair few weeks after birth and is not replaced by terminal hair. Here we report a case of papular atrichia in a 4 year old female child presented with loss of hair and multiple follicular keratotic papules.

Mechanism of JmjC-containing protein Hairless in the regulation of vitamin D receptor function

The JmjC-domain-containing protein Hairless (HR) and the vitamin D receptor (VDR) play a critical role in the maintenance of hair growth. Mutations in HR or VDR cause alopecia in humans and mice. Here we show that HR interacts with VDR and induces VDR relocalization in the nuclei. HR associates and colocalizes with nuclear receptor co-repressor (N-CoR) which is localized to subnuclear structures termed matrix-associated deacetylase (MAD) bodies. It is found that the HR mutants (C622G, N970S, D1012N, V1136D), associated with alopecia universalis congenita (AUC) or atrichia with papular lesions (APL), exhibit an abnormal subcellular distribution in addition to the impaired co-repressor activity with VDR. Studies on deletion mutants of HR indicate that the JmjC domain contributes to the co-repressor activity of HR. Our work provides new clues and evidence for the understanding on the role of HR in hair growth.

Identification of a new mutation in the gene coding for hairless protein responsible for alopecia universalis: The importance of direct gene sequencing

Mutations in the gene HR coding for the hairless protein are associated with atrichia with papular lesions (APL), an autosomal recessive form of alopecia universalis that is characterized by generalized scalp and body atrichia with papular lesions. We here describe a South Italian family of ancient Albanian heritage. The full phenotype with complete atrichia was expressed in 2 siblings, whereas the parents and one sister were unaffected. Direct sequencing of the gene coding for the hairless protein allowed the identification of a new mutation in exon 17. Consistent with the recessive inheritance of the disease, both the siblings were homozygous for the mutation, whereas the parents and the unaffected sister where heterozygous. A relevant discrepancy with a haplotype linkage study is reported, stressing the importance of gene sequencing in genetic diagnosis and counseling because linkage studies can be biased by recombination events.

Detection of a novel missense mutations in atrichia with papular lesions.

Atrichia with papular lesions (APL) is a rare inherited disease characterized by early onset of total hair loss, followed by papular lesions over the extensor areas of the body. Recently, mutations in the human hairless (HR) gene have been implicated in its pathogenesis. The identification of mutations in the HR gene is important for differentiating between APL and alopecia universalis (AU). We compared the HR genes of patients with presumed AU who showed minimal or no response to treatment with the HR genes of healthy controls. The subjects were 11 patients with presumed AU who had not responded to treatments. Fifty healthy people were included as controls for molecular analysis. To screen for mutations, polymerase chain reaction was performed. DNA analysis identified a novel heterozygous G-to-A transition at nucleotide position 191 in exon 5. The mutation was not found in the controls, other AU patients, or any unaffected family members except for the patients' mother and maternal grandfather, who were heterozygous HR gene carriers. Our study identifies a novel missense mutation in exon 5 of the HR gene in a Korean APL patient previously diagnosed as AU.

Atrichia with papular lesions

Atrichia with papular lesions (APL) is a rare autosomal recessive form of irreversible alopecia with onset at few months of age with papular keratin cysts over the body. It is associated with mutation in the Zinc finger domain of the human hairless gene on chromosome region 8p12. An eleven-year-old male presented with extensive alopecia starting at six months of age refractory to the treatment along with keratotic papules on the face and trunk. Biopsy from a papule showed mid-dermal keratin cysts and from the scalp showed few vellus follicles with no terminal hairs. The diagnosis of APL was made based upon the criteria proposed. Vitamin D-dependent rickets was ruled out as it has similar clinical presentation. Accurate diagnosis of APL is required to avoid unnecessary treatment to the patient as it is commonly misdiagnosed as alopecia universalis and treated with systemic steroids.

Atrichia congenita with papular lesions

Atrichia congenita with papular lesions

Mutations in the hairless gene underlie APL in three families of Pakistani origin

Atrichia with papular lesions (APL) (OMIM#209500) is a rare autosomal recessively inherited form of irreversible alopecia characterized by papular lesions of keratin-filled cysts on various regions of the body. Males and females are equally affected and present with a distinct pattern of total hair loss on scalp, axilla and body. It begins shortly after birth with the development of hair loss, and patients are normally devoid of eyelashes and eyebrows. Mutations in the hairless (HR) gene have been previously shown to be responsible for APL. In this study, we studied the molecular basis of APL in three unrelated families of Pakistani origin. Molecular analysis of the HR genes was performed on genomic DNA from probands and family members. DNA sequencing of the HR gene in family A revealed a novel homozygous 2bp deletion in exon 6 leading to a frameshift and a downstream premature termination codon in exon 8 (1782-83delAG). In family B, we identified a novel homozygous deletion of a G nucleotide at the exon 15-intron 15 boundary, termed 3097delG. Family C carries a previously reported missense mutation consisting of an A-to-G transition at nucleotide 276 resulting in the mutation N970S in exon 14. Two mutations identified in this study are novel mutations in the HR gene and extend the body of evidence implicating the hairless gene family in the pathogenesis of human skin disorders. The one previously reported mutation suggests it may represent a recurrent mutation, or alternatively, an allele that is widely dispersed around the world.

Nonsense mutations in the hairless gene underlie APL in five families of Pakistani origin

Atrichia with papular lesions (APL) is a rare autosomal recessive form of inherited alopecia. Affected individuals present with a distinct pattern of total hair loss on the scalp, axilla and body shortly after birth and are essentially devoid of eyelashes and eyebrows. This form of hair loss is irreversible and the histology is consistent with an absence of mature hair follicles. In addition to total atrichia, APL patients also present with papules and follicular cysts filled with cornified material. Mutations in the Hairless (HR) gene have been shown to underlie APL. Here, we studied five unrelated large Pakistani families with clinical manifestations of APL. Based on previous reports of HR mutations in APL, we performed direct DNA sequencing analysis. DNA sequencing of the HR gene in APL patients revealed three novel nonsense mutations in five unrelated families. All affected individuals were homozygous for a nonsense mutation due to C-to-T transitions at different positions in the amino acid sequence. Two families carry the mutation Q323X (CAG-TAG) in exon 3, two families harbor the mutation Q502X (CAG-TAG) in exon 6, and one family had a mutation at R940X (CGA-TGA) in exon 14. Haplotype analysis revealed that all affected individuals of both APL1 and APL16 families were homozygous for the same haplotype, and likewise, the mutation in families APL2 and APL19 was on the same haplotype. We report three novel nonsense mutations in the HR gene in APL. Two of the newly identified mutations, Q323X and Q502X, were found to be shared between unrelated families and marker analysis confirmed an identical homozygous haplotype for APL1 and APL16, and for APL2 and APL19. These findings suggest that Q323X and Q502X did not arise independently, but instead appear to have been propagated in the population. Collectively, these findings contribute further evidence for the involvement of hairless mutations in papular atrichia.

Interactions of the Vitamin D Receptor with the Corepressor Hairless

Atrichia with papular lesions (APL) and hereditary vitamin D-resistant rickets have a similar congenital hair loss disorder caused by mutations in hairless (HR) and vitamin D receptor (VDR) genes, respectively. HR is a VDR corepressor, and it has been hypothesized that VDR.HR suppress gene expression during specific phases of the hair cycle. In this study, we examined the corepressor activity of HR mutants (E583V, C622G, N970S, V1056M, D1012N, V1136D, and Q1176X) previously described as the molecular cause of APL as well as HR variants (P69S, C397Y, A576V, E591G, R620Q, T1022A) due to non-synonymous polymorphisms in the HR gene. We found that the corepressor activities of all but one of the pathogenic HR mutants were completely abolished. HR mutant E583V exhibited normal corepressor activity, suggesting that it may not be pathogenic. In co-immunoprecipitation assays, all of the pathogenic HR mutants bound VDR but exhibited reduced binding to histone deacetylase 1 (HDAC1), suggesting that the impaired corepressor activity is due in part to defective interactions with HDACs. The HR variants exhibited two classes of corepressor activity, those with normal activity (C397Y, E591G, R620Q) and those with partially reduced activity (P69S, A576V, T1022A). All of the variants interacted with VDR and HDAC1 with the exception of P69S, which was degraded. When coexpressed with VDR, all of the HR pathogenic mutants and variants increased the level of VDR protein, demonstrating that this function of HR was not impaired by these mutations. This study of HR mutations provides evidence for the molecular basis of APL.

Molecular basis for the rhino Yurlovo (hr(rhY)) phenotype: severe skin abnormalities and female reproductive defects associated with an insertion in the hairless gene.

In 1989, mice bearing mutations at the hr (hairless) locus were first proposed as a model for the human hair growth disorder papular atrichia, since in both these mice and in corresponding patients, a complete hair loss develops due to disintegration of the normal follicle structure into dermal cysts and so-called utriculi. Recently, the human hairless gene was characterized, and pathogenetic mutations were found to be associated with a recessively inherited form atrichia with papular lesions; however, the functions of hr gene remain unclear. Allelic mutations in the murine hairless gene represent a potentially powerful tool to elucidate the role of the hairless gene protein product in hair follicle physiology. In 1980, several naked animals were discovered in a breeding colony of B10.R109/Y mice maintained in the Laboratory of Experimental Biological Models (L.E.B.M., Yurlovo, Moscow District, Russia). By cross breeding with hairless HRS/J hr/hr mice, this mutation was shown to be allelic with hairless. Here, we describe the molecular basis of the hr(rhY) mutation in mice, which consists of a 13 bp insertion in exon 16 of the hr gene. Histological evaluation of Yurlovo mouse skin revealed some differences as compared to the hairless and rhino mutations, with the formation of dermal megacysts being the most specific peculiarity of the Yurlovo mutation. These results, together with previous studies of hr(rhY)/hr(rhY) mutant mice, suggest that the rhino Yurlovo (hr(rhY)) mutation represents a third and potentially more severe variation of the hairless phenotype.

Identification of mutations in the human hairless gene in two new families with congenital atrichia

Congenital atrichia (AUC) is a form of isolated alopecia with an autosomal recessive mode of inheritance. Patients are born with normal hair but this is shed almost completely during the first weeks or months of life and never regrows. In many families the development of papular lesions is noted as an additional phenotypic feature, which defines a related phenotype designated as atrichia with papular lesions (APL). Using positional cloning strategies and the molecular findings in hairless recessive (hr/hr) mice, an animal model for AUC, mutations in the human hairless gene (HR) have been identified as a cause of AUC and APL. To date, more than 20 different mutations of the HR gene have been reported in AUC and APL including different mutation types scattered over the entire HR gene length. In this report, we describe two families of Saudi Arabian and Jewish Iranian origin comprising a number of individuals with clinical features suggestive of AUC. We therefore hypothesized that affected members may carry mutations in the HR gene. After sequencing the complete coding region of the HR gene in the Saudi Arabian family, we identified a homozygous insertion of a G (c.2661dupG; p.Thr888DfsX38) in exon 12, resulting in a premature stop codon. In a Jewish Iranian patient, we identified a homozygous splice site mutation c.1557-1G > T in intron 4. The latter mutation has been previously reported in a compound heterozygous state. In the present report, we describe the second exonic insertion mutation in the human HR gene and the first mutation in exon 12. Our study emphasizes the importance of sequencing the complete coding sequence and exon/intron junctions in the molecular diagnostics of AUC and APL.