RMRP-related short stature: A report of six additional Japanese individuals with cartilage hair hypoplasia and literature review

Biallelic pathogenic variants in RMRP, the gene encoding the RNA component of RNase mitochondrial RNA processing enzyme complex, have been reported in individuals with cartilage hair hypoplasia (CHH). CHH is prevalent in Finnish and Amish populations due to a founder pathogenic variant, n.71A > G. Based on the manifestations in the Finnish and Amish individuals, the hallmarks of CHH are prenatal-onset growth failure, metaphyseal dysplasia, hair hypoplasia, immunodeficiency, and other extraskeletal manifestations. Herein, we report six Japanese individuals with CHH from four families. All probands presented with moderate short stature with mild metaphyseal dysplasia or brachydactyly. One of them had hair hypoplasia and the other immunodeficiency. By contrast, the affected siblings of two families showed only mild short stature. We also reviewed all previously reported 13 Japanese individuals. No n.71A > G allele was detected. The proportions of Japanese versus Finnish individuals were 0% versus 70% for birth length < -2.0 SD, 84% versus 100% for metaphyseal dysplasia and 26% versus 88% for hair hypoplasia. Milder manifestations in the Japanese individuals may be related to the difference of genotypes. The mildest form of CHH phenotypes is mild short stature without overt skeletal alteration or extraskeletal manifestation and can be termed "RMRP-related short stature".

Altered oral microbiome, but normal human papilloma virus prevalence in cartilage-hair hypoplasia patients

BACKGROUND

Cartilage-hair hypoplasia (CHH) is a rare syndromic immunodeficiency with metaphyseal chondrodysplasia and increased risk of malignancy. In this cross-sectional observational study, we examined HPV status and oral microbiome in individuals with CHH. Oral brush samples were collected from 20 individuals with CHH (aged 5-59 years) and 41 controls (1-69 years). Alpha HPVs (43 types) were tested by nested PCR followed by bead-based probe hybridization. Separately, beta-, gamma-, mu- and nu- HPV types were investigated, and a genome-based bacterial microbiome sequencing was performed.

RESULTS

We found a similar alpha HPV prevalence in individuals with CHH (45%) and controls (36%). The HPV types of individuals with CHH were HPV-16 (25%), 27, 28, and 78, and of controls HPV-3, 16 (21%), 27, and 61. Beta HPV positivity and combined beta/gamma/mu/nu prevalence was detected in 11% and 11% of individuals with CHH and in 5% and 3% of the controls, respectively. Individuals with CHH differed from the controls in bacterial microbiota diversity, richness, and in microbial composition. Individuals with CHH had lower abundance of species Mitsuokella sp000469545, Parascardovia denticolens, Propionibacterium acidifaciens, UMGS1907 sp004151455, Salinicola halophilus, Haemophilus_A paraphrohaemolyticus, Fusobacterium massiliense, and Veillonella parvula, and higher abundance of Slackia exigua.

CONCLUSIONS

Individuals with CHH exhibit similar prevalence of HPV DNA but different bacterial microbiota on their oral mucosa compared to healthy controls. This may partly explain the previously observed high prevalence of oral diseases in CHH, and regular oral examination is warranted.

Assessment of the Genetic Spectrum of Uncombable Hair Syndrome in a Cohort of 107 Individuals

Importance

Uncombable hair syndrome (UHS) is a rare hair shaft anomaly that manifests during infancy and is characterized by dry, frizzy, and wiry hair that cannot be combed flat. Only about 100 known cases have been reported so far.

Objective

To elucidate the genetic spectrum of UHS.

Design, Setting, and Participants

This cohort study includes 107 unrelated index patients with a suspected diagnosis of UHS and family members who were recruited worldwide from January 2013 to December 2021. Participants of all ages, races, and ethnicities were recruited at referral centers or were enrolled on their own initiative following personal contact with the authors. Genetic analyses were conducted in Germany from January 2014 to December 2021.

Main Outcomes and Measures

Clinical photographs, Sanger or whole-exome sequencing and array-based genotyping of DNA extracted from blood or saliva samples, and 3-dimensional protein modeling. Descriptive statistics, such as frequency counts, were used to describe the distribution of identified pathogenic variants and genotypes.

Results

The genetic characteristics of patients with UHS were established in 80 of 107 (74.8%) index patients (82 [76.6%] female) who carried biallelic pathogenic variants in PADI3, TGM3, or TCHH (ie, genes that encode functionally related hair shaft proteins). Molecular genetic findings from 11 of these 80 individuals were previously published. In 76 (71.0%) individuals, the UHS phenotype were associated with pathogenic variants in PADI3. The 2 most commonly observed PADI3 variants account for 73 (48.0%) and 57 (37.5%) of the 152 variant PADI3 alleles in total, respectively. Two individuals carried pathogenic variants in TGM3, and 2 others carried pathogenic variants in TCHH. Haplotype analyses suggested a founder effect for the 4 most commonly observed pathogenic variants in the PADI3 gene.

Conclusions and Relevance

This cohort study extends and gives an overview of the genetic variant spectrum of UHS based on molecular genetic analyses of the largest worldwide collective of affected individuals, to our knowledge. Formerly, a diagnosis of UHS could only be made by physical examination of the patient and confirmed by microscopical examination of the hair shaft. The discovery of pathogenic variants in PADI3, TCHH, and TGM3 may open a new avenue for clinicians and affected individuals by introducing molecular diagnostics for UHS.

Lymphomas in cartilage-hair hypoplasia – A case series of 16 patients reveals advanced stage DLBCL as the most common form

Background

Patients with cartilage-hair hypoplasia (CHH) have an increased risk of malignancy, particularly non-Hodgkin lymphoma and basal cell carcinoma. The characteristics, clinical course, response to therapy and outcome of lymphomas in CHH remains unexplored.

Methods

We assessed clinical features of lymphoma cases among Finnish patients with CHH. Data were collected from the Finnish Cancer Registry, hospital records, the National Medical Databases and Cause-of-Death Registry of Statistics Finland.

Results

Among the 160 CHH patients, 16 (6 men, 10 women) were diagnosed with lymphoma during 1953-2016. Lymphoma was diagnosed in young adulthood (median age 26.4 years, range from 6.4 to 69.5 years), mostly in advanced stage. The most common lymphoma type was diffuse large cell B-cell lymphoma (DLBCL) (6/16, 38%). Eight patients received chemotherapy (8/16, 50%), and two of them survived. Standard lymphoma chemotherapy regimens were administered in the majority of cases. Altogether, eleven CHH patients died due to lymphomas (11/16, 69%). In almost all surviving lymphoma patients, the diagnosis was made either during routine follow-up or after evaluation for non-specific mild symptoms. Search for CHH-related clinical predictors demonstrated higher prevalence of recurrent respiratory infections, in particular otitis media, and Hirschsprung disease in patients with lymphoma. However, three patients had no clinical signs of immunodeficiency prior to lymphoma diagnosis.

Conclusion

DLBCL is the most common type of lymphoma in CHH. The outcome is poor probably due to advanced stage of lymphoma at the time of diagnosis. Other CHH-related manifestations poorly predicted lymphoma development, implying that all CHH patients should be regularly screened for malignancy.

Uncombable hair syndrome and beyond

Uncombable hair syndrome presents with frizzy hair in early childhood. Isolated hair manifestations are usually observed; however, systemic involvement of the nervous system, eyes, and ears have also been reported. The syndrome has been classified into three subtypes, correlating with the three mutated genes: peptidyl arginine deiminase, type III; transglutaminase 3; and trichohyalin. This article presents the clinical picture of uncombable hair syndrome with special attention to its systemic manifestations. It also addresses its molecular aspects. Google Scholar was used to retrieve relevant publications. Clinical and molecular data were tabulated and frequencies were calculated. At least 127 cases were identified. Congenital hair defects were reported in two-thirds of cases, in which hair texture (83%), color (52%), density (15%), and growth (11%) were impaired. Uncombable hair rarely involves the eyebrows and eyelashes, and it may co-occur with loose anagen hair syndrome, androgenic alopecia, alopecia areata, and scarring alopecia. Pathologies of the skin, nails, and teeth were reported among 63%, 28%, and 25%, respectively. Systemic abnormalities were not uncommon. Dysmorphic features (n = 8), and neuropsychiatric/developmental (n = 8), ophthalmic (n = 7), otic (n = 4), and cardiopulmonary (n = 3) manifestations were also reported. Molecular genetic analysis of all patients is recommended to identify genotype-phenotype correlation. A general pediatric review might be needed to rule out any potential systemic association.

A disease-linked lncRNA mutation in RNase MRP inhibits ribosome synthesis

RMRP encodes a non-coding RNA forming the core of the RNase MRP ribonucleoprotein complex. Mutations cause Cartilage Hair Hypoplasia (CHH), characterized by skeletal abnormalities and impaired T cell activation. Yeast RNase MRP cleaves a specific site in the pre-ribosomal RNA (pre-rRNA) during ribosome synthesis. CRISPR-mediated disruption of RMRP in human cells lines caused growth arrest, with pre-rRNA accumulation. Here, we analyzed disease-relevant primary cells, showing that mutations in RMRP impair mouse T cell activation and delay pre-rRNA processing. Patient-derived human fibroblasts with CHH-linked mutations showed similar pre-rRNA processing delay. Human cells engineered with the most common CHH mutation (70AG in RMRP) show specifically impaired pre-rRNA processing, resulting in reduced mature rRNA and a reduced ratio of cytosolic to mitochondrial ribosomes. Moreover, the 70AG mutation caused a reduction in intact RNase MRP complexes. Together, these results indicate that CHH is a ribosomopathy.

Cartilage-hair Hypoplasia Complicated with Liver Cirrhosis Due to Chronic Intrahepatic Cholestasis

We herein report a rare case of cartilage-hair hypoplasia (CHH) complicated with liver cirrhosis. A 20-year-old Japanese man with CHH was found incidentally to have liver cirrhosis and an esophageal varix. This patient had been treated for infections due to immunodeficiency since early childhood. He ultimately died of liver failure at 31 years of age. An autopsy revealed an abnormality of the interlobular bile ducts and intrahepatic cholestasis. Liver cirrhosis was thought to have been caused by chronic intrahepatic cholestasis due to biliary duct hypoplasia and changes in the intestinal microbiome. Therefore, CHH may cause biliary cirrhosis due to multiple effects.

Pulmonary Follow-Up Imaging in Cartilage-Hair Hypoplasia: a Prospective Cohort Study

Cartilage-hair hypoplasia is a syndromic immunodeficiency with short stature, chondrodysplasia, and variable degree of immune dysfunction. Patients with cartilage-hair hypoplasia are prone to recurrent respiratory tract infections, and the prevalence of bronchiectasis ranges from 29 to 52%. Pulmonary complications contribute significantly to the mortality; therefore, regular lung imaging is essential. However, the optimal schedule for repeated lung imaging remains unestablished. We determined the rate and correlates of progression of structural lung changes in a prospectively followed cohort of 16 patients with cartilage-hair hypoplasia. We analyzed clinical, laboratory, and pulmonary functional testing data and performed lung magnetic resonance imaging at a median interval of 6.8 years since previous imaging. Imaging findings remained identical or improved due to disappearance of inflammatory changes in all evaluated patients. Patients with subtle signs of bronchiectasis on imaging tended to have low immunoglobulin M levels, as well as suffered from pneumonia during the follow-up. In conclusion, our results suggest slow if any development of bronchiectasis in selected subjects with cartilage-hair hypoplasia.

Craniofacial and Craniocervical Features in Cartilage-Hair Hypoplasia: A Radiological Study of 17 Patients and 34 Controls

BACKGROUND

Biallelic mutations in the non-coding RNA gene RMRP cause Cartilage-hair hypoplasia (CHH), a rare skeletal dysplasia in which the main phenotypic characteristic is severe progressive growth retardation.

OBJECTIVE

This study compared the cranial dimensions of individuals with CHH to healthy subjects.

METHODS

Lateral skull radiographs of 17 patients with CHH (age range 10 to 59 years) and 34 healthy individuals (age range 10 to 54 years) were analyzed for relative position of the jaws to skull base, craniofacial height and depth, as well as vertical growth pattern of the lower jaw, anterior cranial base angle, and the relationship between the cervical spine and skull base.

RESULTS

We found that the length of the upper and lower jaws, and clivus were significantly decreased in patients with CHH as compared to the controls. Anterior cranial base angle was large in patients with CHH. Basilar invagination was not found.

CONCLUSION

This study found no severe craniofacial involvement of patients with CHH, except for the short jaws. Unexpectedly, mandibular deficiency did not lead to skeletal class II malocclusion.

CLINICAL IMPACT

Although the jaws were shorter in patients with CHH, they were proportional to each other. A short posterior cranial base was not associated with craniocervical junction pathology.

How Altered Ribosome Production Can Cause or Contribute to Human Disease: The Spectrum of Ribosomopathies

A number of different defects in the process of ribosome production can lead to a diversified spectrum of disorders that are collectively identified as ribosomopathies. The specific factors involved may either play a role only in ribosome biogenesis or have additional extra-ribosomal functions, making it difficult to ascribe the pathogenesis of the disease specifically to an altered ribosome biogenesis, even if the latter is clearly affected. We reviewed the available literature in the field from this point of view with the aim of distinguishing, among ribosomopathies, the ones due to specific alterations in the process of ribosome production from those characterized by a multifactorial pathogenesis.

Female Androgenetic Alopecia: An Update on Diagnosis and Management

Female androgenetic alopecia (FAGA) is a common cause of non-scarring alopecia in women. The onset may be at any age following puberty and the frequency increases with age. Clinically, it shows a diffuse hair thinning over the central scalp, while the frontal hairline is usually retained. FAGA can have a significant psychological impact, leading to anxiety and depression. For this reason, early diagnosis is very important to stop the progression of the disease. The sex hormonal milieu is the main pathogenetic mechanism studied in FAGA. The role of androgens is not clearly defined and only one-third of women with FAGA show abnormal androgen levels. Endocrinological diseases with hyperandrogenism associated with FAGA comprise polycystic ovarian syndrome (PCOS), hyperprolactinemia, adrenal hyperplasia and, rarely, ovarian and adrenal tumours. Usually the diagnosis of FAGA is made clinically. A complete clinical examination and a blood examination can reveal other signs of hyperandrogenism. Trichoscopy shows the typical hair miniaturization. A scalp biopsy can be useful when the clinical evaluation does not provide a definitive diagnosis or when cicatricial alopecias with hair loss in the distribution of FAGA or alopecia areata are suspected. FAGA is a slowly progressive disease. The goal of therapy is to stop the progression and to induce a cosmetically acceptable hair regrowth. The most important drugs are topical minoxidil and oral anti-androgens. The purpose of this review is to provide an update on FAGA and to create a guideline on diagnosis and management of this frequent hair disease, not always easily recognizable from cicatricial alopecias with a similar distribution.

Woolly hair nevus: case report and review of literature

Woolly hair nevus consists of a patch of curly and hypopigmented hair that is restricted to an area of the scalp. It is usually benign but it can be associated with other systemic findings. Trichoscopy and dermoscopy may be useful when analyzing this entity. The authors describe a case of woolly hair nevus in a 5-year-old boy and present a review of the literature of woolly hair nevus, including classification, histopathology, associated systemic findings, and the recent described genetic mutations.

[A girl with unruly hair]

Uncombable hair syndrome (UHS) is an uncommon hair anomaly that can cause significant psychosocial burden. Defects in hair shaft proteins cause hairs to be frizzy and difficult to comb flat. UHS occurs in children and improves with age. We describe a case of a 3-year-old girl with UHS.

Congenital Hypopigmentary Disorders with Multiorgan Impairment: A Case Report and an Overview on Gray Hair Syndromes

The term congenital hypopigmentary disorders refers to a wide group of heterogeneous hereditary diseases, clinically characterized by inborn pigmentary defects of the iris, hair, and/or skin. They include Gray Hair Syndromes (GHSs), a rare group of autosomal recessive genodermatosis hallmarked by inborn silvery gray hair. GHSs encompass Griscelli, Chediak⁻Higashi, Elejalde, and Cross syndromes, which are all characterized by a broad spectrum of severe multisystem disorders, including neurological, ocular, skeletal, and immune system impairment. In this manuscript, we describe in detail the clinical, trichoscopic, and genetic features of a rare case of Griscelli syndrome; moreover, we provide an overview of all the GHSs known to date. Our report highlights how an accurate clinical examination with noninvasive methods, like trichoscopy, may play a crucial rule in diagnosis of rare and potentially lethal genetic syndromes such as Griscelli syndrome, in which timely diagnosis and therapy may modify the clinical course, quality of life, and likelihood of survival.

Rubella Virus-Associated Cutaneous Granulomatous Disease: a Unique Complication in Immune-Deficient Patients, Not Limited to DNA Repair Disorders

The association of immunodeficiency-related vaccine-derived rubella virus (iVDRV) with cutaneous and visceral granulomatous disease has been reported in patients with primary immunodeficiency disorders (PIDs). The majority of these PID patients with rubella-positive granulomas had DNA repair disorders. To support this line of inquiry, we provide additional descriptive data on seven previously reported patients with Nijmegen breakage syndrome (NBS) (n = 3) and ataxia telangiectasia (AT) (n = 4) as well as eight previously unreported patients with iVDRV-induced cutaneous granulomas and DNA repair disorders including NBS (n = 1), AT (n = 5), DNA ligase 4 deficiency (n = 1), and Artemis deficiency (n = 1). We also provide descriptive data on several previously unreported PID patients with iVDRV-induced cutaneous granulomas including cartilage hair hypoplasia (n = 1), warts, hypogammaglobulinemia, immunodeficiency, myelokathexis (WHIM) syndrome (n = 1), MHC class II deficiency (n = 1), Coronin-1A deficiency (n = 1), X-linked severe combined immunodeficiency (X-SCID) (n = 1), and combined immunodeficiency without a molecular diagnosis (n = 1). At the time of this report, the median age of the patients with skin granulomas and DNA repair disorders was 9 years (range 3-18). Cutaneous granulomas have been documented in all, while visceral granulomas were observed in six cases (40%). All patients had received rubella virus vaccine. The median duration of time elapsed from vaccination to the development of cutaneous granulomas was 48 months (range 2-152). Hematopoietic cell transplantation was reported to result in scarring resolution of cutaneous granulomas in two patients with NBS, one patient with AT, one patient with Artemis deficiency, one patient with DNA Ligase 4 deficiency, one patient with MHC class II deficiency, and one patient with combined immunodeficiency without a known molecular etiology. Of the previously reported and unreported cases, the majority share the diagnosis of a DNA repair disorder. Analysis of additional patients with this complication may clarify determinants of rubella pathogenesis, identify specific immune defects resulting in chronic infection, and may lead to defect-specific therapies.

Novel mutations in the lipase H gene lead to secretion defects of LIPH in Chinese patients with autosomal recessive woolly hair/hypotrichosis (ARWH/HT)

Autosomal recessive woolly hair/hypotrichosis (ARWH/HT: OMIM #278150/604379) is a rare hereditary hair disease characterized by tightly curled hair at birth which can lead to sparse hair later in life. The mutations in both LIPH and LPAR6/P2RY5 are responsible for autosomal recessive woolly hair with or without hypotrichosis (ARWH/HT). To conduct clinical and genetic investigations in four patients from three unrelated Chinese Han families with ARWH/HT, we performed mutation screening of LIPH and LPAR6/P2RY5 gene and identified four mutations in LIPH: c.454G>A, c.614A>G, c.736T>A, c.742C>A. c.736T>A and c.742C>A mutations were reported in previous studies, and c.454G>A, c.614A>G were identified for the first time. We carried out functional studies of the two mutants with c.454G>A (p.Gly152Arg, G152R) or c.614A>G (p.His205Arg, H205R). Interestingly, both of them lead to secretion defects of LIPH, which are involved in the pathogenesis of ARWH/HT.

The dental phenotype of hairless dogs with FOXI3 haploinsufficiency

Hairless dog breeds show a form of ectodermal dysplasia characterised by a lack of hair and abnormal tooth morphology. This has been attributed to a semi-dominant 7-base-pair duplication in the first exon of the forkhead box I3 gene (FOXI3) shared by all three breeds. Here, we identified this FOXI3 variant in a historical museum sample of pedigreed hairless dog skulls by using ancient DNA extraction and present the associated dental phenotype. Unlike in the coated wild type dogs, the hairless dogs were characterised in both the mandibular and maxillary dentition by a loss of the permanent canines, premolars and to some extent incisors. In addition, the deciduous fourth premolars and permanent first and second molars consistently lacked the distal and lingual cusps; this resulted in only a single enlarged cusp in the basin-like heel (talonid in lower molars, talon in upper molars). This molar phenotype is also found among several living and fossil carnivorans and the extinct order Creodonta in which it is associated with hypercarnivory. We therefore suggest that FOXI3 may generally be involved in dental (cusp) development within and across mammalian lineages including the hominids which are known to exhibit marked variability in the presence of lingual cusps.

Systematic screening for skin, hair, and nail abnormalities in a large-scale knockout mouse program

The International Knockout Mouse Consortium was formed in 2007 to inactivate (“knockout”) all protein-coding genes in the mouse genome in embryonic stem cells. Production and characterization of these mice, now underway, has generated and phenotyped 3,100 strains with knockout alleles. Skin and adnexa diseases are best defined at the gross clinical level and by histopathology. Representative retired breeders had skin collected from the back, abdomen, eyelids, muzzle, ears, tail, and lower limbs including the nails. To date, 169 novel mutant lines were reviewed and of these, only one was found to have a relatively minor sebaceous gland abnormality associated with follicular dystrophy. The B6N(Cg)-Far2^{tm2b(KOMP)Wtsi}/2J strain, had lesions affecting sebaceous glands with what appeared to be a secondary follicular dystrophy. A second line, B6N(Cg)-Ppp1r9b^{tm1.1(KOMP)Vlcg}/J, had follicular dystrophy limited to many but not all mystacial vibrissae in heterozygous but not homozygous mutant mice, suggesting that this was a nonspecific background lesion. We discuss potential reasons for the low frequency of skin and adnexal phenotypes in mice from this project in comparison to those seen in human Mendelian diseases, and suggest alternative approaches to identification of human disease-relevant models.

Unusual manifestations of ectodermal dysplasia-syndactyly syndrome type I in two Yemeni siblings

Ectodermal dysplasias (EDs) are a group of genodermatoses characterized by malformations of tissues derived from the ectoderm, including the skin, its appendages (hair, nails, sweat glands), teeth, and the breasts. Ectodermal dysplasia syndactyly syndrome (EDSS) is a rare, newly described type of ED involving syndactyly. We report 2 Yemeni siblings with typical EDSS manifestations, including bilateral, partial cutaneous syndactyly of the fingers and toes; sparse, coarse, brittle scalp hair, eyebrows, and eyelashes; and conical, widely spaced teeth with enamel notches. In addition, the siblings presented with other features hitherto not described for this syndrome, such as adermatoglyphia, onychogryphosis, hypoplastic widely spaced nipples, hypoplastic thumbs, and red scalp hair.

Pseudohypoparathyroidism vs. tricho-rhino-phalangeal syndrome: patient reclassification

OBJECTIVES

Given that tricho-rhino-phalangeal syndrome (TRPS) and pseudohypoparathyroidism/pseudopseudohypoparathyroidism (PHP/PPHP) are very rare monogenic disorders that share some features (distinctive facies, short stature, brachydactyly and, in some patients, intellectual disability) that lead to their misdiagnosis in some cases, our objective was to identify clinical, biochemical or radiological signs that could help to distinguish these two syndromes.

METHODS AND RESULTS

We report on two cases, which were referred to the Endocrinology and Pediatric Endocrinology Services for obesity. Clinical evaluation initially suggested the diagnosis of PHP-Ia [phenotype suggestive of Albright hereditary osteodystrophy (AHO) with parathyroid hormone (PTH) resistance] and PPHP (phenotype resembling AHO, without PTH resistance), but (epi)genetic analysis of the GNAS locus ruled out the suspected diagnosis. Further clinical re-evaluation prompted us to suspect TRPS, and this was confirmed genetically.

CONCLUSION

TRPS was mistakenly identified as PHP/PPHP because of the coexistence of obesity and brachydactyly, with PTH resistance in one of the cases. Specific traits such as sparse scalp hair and a pear-shaped nose, present in both cases, can be considered pathognomonic signs of TRPS, which could help us to reach a correct diagnosis.

Phenotype and genotype in Nicolaides-Baraitser syndrome

Nicolaides-Baraitser syndrome (NCBRS) is an intellectual disability (ID)/multiple congenital anomalies syndrome caused by non-truncating mutations in the ATPase region of SMARCA2, which codes for one of the two alternative catalytic subunits of the BAF chromatin remodeling complex. We analyzed 61 molecularly confirmed cases, including all previously reported patients (n = 47) and 14 additional unpublished individuals. NCBRS is clinically and genetically homogeneous. The cardinal features (ID, short stature, microcephaly, typical face, sparse hair, brachydactyly, prominent interphalangeal joints, behavioral problems and seizures), are almost universally present. There is variability however, as ID can range from severe to mild, and sparse hair may be present only in certain age groups. There may be a correlation between the severity of the ID and presence of seizures, absent speech, short stature and microcephaly. SMARCA2 mutations causing NCBRS are likely to act through a dominant-negative effect. There may be some genotype-phenotype correlations (mutations at domain VI with severe ID and seizures; mutations affecting residues Pro883, Leu946, and Ala1201 with mild phenotypes) but numbers are still too small to draw definitive conclusions.

The tricho-rhino-phalangeal syndrome: oral manifestations and management

Tricho-rhino-phalangeal Syndrome (TRPS) is a rare inherited dysplasia affecting hair, nasal structure and fingers. A literature review indicated that since first described, three types of manifestations have been identified. A Table summarising the oral manifestations demonstrates the variety of presentations. A South African male child presented with the syndrome and was found to show premature eruption of permanent teeth, a finding that has not been previously reported. His oro-facial manifestations also included malaligned and unerupted crowded teeth, bulbosity of the nasal tip and an elongated philtrum and evidence of mild intellectual impairment. A protocol has been developed to guide the future management of these cases.

Highly prevalent LIPH founder mutations causing autosomal recessive woolly hair/hypotrichosis in Japan and the genotype/phenotype correlations

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.

Alopecia in genetic diseases

Congenital abnormalities of the hair shaft are conditions in most cases linked to chemical, biochemical, and morphological alterations, genetically determined. These alterations may be associated with a larger array of symptoms, as mentioned above, or may occur isolated. The number of genes involved and their penetration are responsible for the mode of transmission, severity, and phenotypic expression of the disease. Furthermore, in some cases, these abnormalities can be considered true pathognomonic markers of disease. Within this disorder, two groups are classically identified: with increased fragility of the hair shaft and without increased fragility. Congenital abnormalities of the hair shaft that present an increased fragility of hair include: Trichorrhexis nodosa congenita, Trichoschisis, Trichorrhexis invaginata, Trichothiodystrophy, Trichoclasia, Pili torti, Monilethrix and Loose anagen syndrome; while the alterations that are not associated with a greater fragility of the hair are: Pili annulati, Longitudinal grooves, Uncombable hair syndrome (Pili trianguli et canaliculi), Woolly hair, Woolly hair with dominant inheritance, Familial recessive woolly hair and Woolly hair nevus.

Hair loss in infancy

Hair diseases represent a significant portion of cases seen by pediatric dermatologists although hair has always been a secondary aspect in pediatricians and dermatologists training, on the erroneous basis that there is not much information extractable from it. Dermatologists are in the enviable situation of being able to study many disorders with simple diagnostic techniques. The hair is easily accessible to examination but, paradoxically, this approach is often disregarded by non-dermatologist. This paper has been written on the purpose of trying to serve in the diagnostic process of daily practice, and trying to help, for example, to distinguish between certain acquired and some genetically determined hair diseases. We will focus on all the data that can be obtained from our patients' hair and try to help on using the messages given by hair for each patient. Quite often it is extremely hard to distinguish between abnormality and normality in neonatal hair aspects. We will specially focus in the most common physiological changes that may mislead to an incorrect diagnosis. Specific treatment for those hair diseases that do have one, and basic general approach to improve the cosmetic appearance of hair, will be also be discussed for those hair disturbances that do not have a specific treatment.

The appearance of pili annulati following alopecia areata

Pili annulati is a rare autosomal-dominant hair shaft abnormality. It is characterized by alternating light and dark bands along the shaft due to air-filled cavities within the cortex of the hair shaft. Alopecia areata has been previously described as a common association with pili annulati, with improvement in alopecia areata coinciding with resolution of pili annulati. We report the case of a patient with a history of alopecia areata and alopecia universalis who developed the characteristic banded hair of pili annulati upon resolution of her alopecia areata. We provide direct microscopic examination of postregrowth hairs compared to normal and cross-polarized light microscopy.

A case of onycotricodysplasia with intellectual disability, without neutropenia

Onychotrichodysplasia, a rare autosomal recessive disorder, presents with hypoplastic fingernails, trichorrhexis, chronic neutropenia, and psychomotor retardation. Here, we describe a rare presentation of a child with onycotrichodysplasia associated with intellectual disability, but without neutropenia. He had sparse, short, dry, curly hair, dysplastic nails and intellectual disability. In contrast to cases described earlier, our patient had normal neutrophil count.

Hair and nails

BACKGROUND

Hair and nails are elements of dermatology that can often be omitted from the dermatological assessment. However, there are common and distressing hair and nail conditions that require diagnosis and management.

OBJECTIVE

This article considers common and important hair and nail presentations to general practice. General and specific conditions will be discussed.

DISCUSSION

Hair conditions may have significant psychological implications. This article considers assessment and management of conditions of too much hair, hair loss or hair in the wrong places. It also considers the common nail conditions seen in general practice and provides a guide to diagnosis and management.

The molecular basis of the cartilage-hair hypoplasia-anauxetic dysplasia spectrum

Cartilage-hair hypoplasia and anauxetic dysplasia are two autosomal recessive skeletal dysplasias characterized by different degrees from metaphyseal to spondylo-meta-epiphyseal dysplasia and variable additional features including predisposition to cancer, anemia, immunodeficiency, and gastrointestinal malabsorption and Hirschsprung's disease. Both are caused by mutations in the untranslated RMRP gene, which forms the RNA subunit of the RNase MRP complex. This complex is involved in the ribosome assembly by cleavage of 5.8S rRNA, cell cycle control by Cyclin B2 mRNA cleavage at the end of mitosis, processing the mitochondrial RNA, and forming a complex with hTERT suggesting a possible involvement in expression regulation by siRNA synthesis. The degree of skeletal dysplasia correlates mainly with the rRNA cleavage activity, whereas significantly diminished mRNA cleavage activity is a prerequisite for immunodeficiency. Thus, the clinical phenotype emerges in most cases of the combined effect on the respective effect on RNase MRP function.

[Cartilage-hair hypoplasia--much more than growth problem]

Cartilage-hair hypoplasia (CHH) is an autosomal recessive metaphyseal chondrodysplasia caused by mutations in the RMRP gene encoding the RNA component of a mitochondrial ribonuclease complex. CHH is particularly prevalent among the Old Order Amish and the Finns. CHH is characterized by severe short-limbed short stature, sparse hair, defective immunity involving both cellular and humoral components, and defective erytropoiesis. Cancer incidence is 7-fold higher in patients with CHH as compared with the normal population. Especially non-Hodgkin lymphoma and basal cell carcinoma are frequent. Patients with CHH need close follow-up also in adulthood.

Poland syndrome: rare presentation in two cases

Poland syndrome was first described in 1840 by Alfred Poland while still a medical student and the other components of the syndrome were described at London Guy's Hospital following the dissection of a cadaver's hand, which had hypoplasia and syndactyly. The incidence of Poland syndrome has been reported to be 1 in 30,000 live births. In the present case report, two Poland syndrome patients with ipsilateral hypomastia and a reduction in the axillary/pectoral hairs diagnosed during adulthood are presented; one patient was affected on the left side and had widespread cafe au lait spots, and the other patient had respiratory dysfunction due to multiple rib anomalies.

Loose anagen hair syndrome: an unusual cause of alopecia of cosmetic importance only

A 5-year-old girl was referred to our clinic because of a 5-month history of diffuse hair loss. Her hair was light brown and dull with evident patches of alopecia. There were no signs of scalp inflammation or scarring. A hair pull test revealed multiple hairs, easily and painlessly extracted. Light microscopic examination and trichogram were consistent with loose anagen hair syndrome. This is an unusual benign hair disorder of childhood that improves spontaneously with aging.

Pili torti: clinical findings, associated disorders, and new insights into mechanisms of hair twisting

Pili torti is a hair shaft disorder characterized by hair that does not grow long and is easily broken; the hair often has a coarse or spangled appearance. A diagnosis is made by light microscopy of flattened hair twisted 1800 along its axis. Although pili torti may be isolated, it is commonly associated with other congenital defects and therefore, if identified, further evaluation for possible neurologic deficits and ectodermal disorders is an important part of the clinical evaluation. Alterations of the inner root sheath likely lead to the abnormal molding and twisting of the hair shaft. More recent research suggests that these alterations may occur in the face of mitochondrial dysfunction and may be influenced by the presence of reactive oxygen species.

Mild clinical phenotype and subtle radiographic findings in an infant with cartilage-hair hypoplasia

Cartilage-hair hypoplasia (CHH) is one of the well-known immuno-osseous dysplasias (IOD), which are a combination of skeletal dysplasia and immunodeficiency. It is characterized by disproportionate short stature, fine sparse hair, ligamentous laxity, hematological abnormalities with anemia, a predisposition to malignant tumors, and recurrent infections usually due to cellular and/or humoral immunodeficiency. However, there is a significant overlap of clinical findings among the other IODS such as Schimke's IOD. Here, we present a case of CHH with mild skeletal changes and immunological findings associated with recurrent otitis media, neutropenia, and lymphopenia. With this report, we once more emphasize the difficulty in assessing young individuals with CHH presenting with mild ectodermal findings and subtle radiographic changes.

The cutaneous epidermal growth factor network: Can it be translated clinically to stimulate hair growth?

The influences exerted by the epidermal growth factor receptor (EGFR) on the skin act at multiple levels, which involve compartments that normally express EGFR. These include the basal and suprabasal layers of the epidermis, sebaceous glands, and the outer root sheath of the hair follicles. The physiological roles of EGFR ensure epidermal renewal and integrity, along with a gatekeeping and function and hair growth stimulation functions. Important cellular functions that are altered during EGF receptor blocking therapy consist of epidermal differentiation, proliferation, apoptosis, and migration, with an overall dominating effect of inducing growth arrest and terminal differentiation of the keratinocytes in the basal layers. The effects of EGFR blockage on the hair cycle include terminal differentiation of the hair follicle, which in certain cases may be associated with trichomegaly. Trichomegaly of the eyelashes may occur as an isolated occurrence or, frequently, as part of a generalized phenomenon that may be associated with the use of the EGFR inhibitors. Molecular changes associated with EGFR blockage are discussed, relevant to their association with hair growth. Modulation of Akt, AP2alpha, CDK4, Notch-1, p27KIP1, and Hedgehog expression are involved in the initiation of the hair cycle and inducement of the anagen phase, followed by proliferation and differentiation of the hair follicles. Epidermal growth factor receptor inhibitors have been developed as therapeutic molecules directed against cancer; in these regimens the knowledge of EGF receptor signaling functions has been translated into significant clinical results. However, among their various collateral effects on the skin, hair growth is observed to occur in certain patients. A particular "wavy" hair phenotype is observed during the pharmacological EGFR receptor blockade, just as in murine transgenic models that carry loss of function of TGF-alpha or EGFR genes. A better characterization of the individual roles pertaining to the EGF family ligands and receptors, has the potential provide new strategies for the management of hair loss.

Tay syndrome

Tay syndrome or IBIDS is a rare autosomal recessive genetic disorder characterized by congenital ichthyosis and abnormal brittle hair (trichothiodystrophy). Other features include photosensitivity, abnormal nails and multiple developmental defects affecting organs mainly derived from neuroectoderm. The exact prevalence of this condition is not known, but up to 1991, clinical data of 15 cases with IBIDS were published .We report a case of Tay syndrome with additional features of Duane's retraction syndrome and Perthes disease, which have not yet been reported in literature.

TGF-β superfamily signaling is essential for tooth and hair morphogenesis and differentiation

Members of the transforming growth factor beta (TGF-beta) superfamily of signaling molecules are involved in the regulation of many developmental processes that involve the interaction between mesenchymal and epithelial tissues. Smad7 is a potent inhibitor of many members of the TGF-beta family, notably TGF-beta and activin. In this study, we show that embryonic overexpression of Smad7 in stratified epithelia using a keratin 5 promoter, results in severe morphogenetic defects in skin and teeth and leads to embryonic and perinatal lethality. To further analyze the functions of Smad7 in epithelial tissues of adult mice, we used an expression system that allowed a controlled overexpression of Smad7 in terms of both space and time. Skin defects in adult mice overexpressing Smad7 were characterized by hyper-proliferation and missing expression of early markers of keratinocyte differentiation. Upon Smad7-mediated blockade of TGF-beta superfamily signaling, ameloblasts failed to produce an enamel layer in incisor teeth. In addition, TGF-beta blockade in adult mice altered the pattern of thymic T cell differentiation and the number of thymic T cells was significantly reduced. This study shows that TGF-beta superfamily signaling is essential for development of hair, tooth and T-cells as well as differentiation and proliferation control in adult tissues.