Short anagen hair syndrome: association with mono- and biallelic variants in WNT10A and a genetic overlap with male pattern hair loss.

BACKGROUND: Short anagen hair (SAH) is a rare paediatric hair disorder characterized by a short anagen phase, an inability to grow long scalp hair and a negative psychological impact. The genetic basis of SAH is currently unknown. OBJECTIVES: To perform molecular genetic investigations in 48 individuals with a clinical phenotype suggestive of SAH to identify, if any, the genetic basis of this condition. METHODS: Exome sequencing was performed in 27 patients diagnosed with SAH or with a complaint of short, nongrowing hair. The cohort was screened for variants with a minor allele frequency (MAF) < 5% in the general population and a Combined Annotation Dependent Depletion (CADD) score > 15, to identify genes whose variants were enriched in this cohort. Sanger sequencing was used for variant validation and screening of 21 additional individuals with the same clinical diagnosis and their relatives. Genetic association testing of SAH-related variants for male pattern hair loss (MPHL) was performed using UK Biobank data. RESULTS: Analyses revealed that 20 individuals (42%) carried mono- or biallelic pathogenic variants in WNT10A. Rare WNT10A variants are associated with a phenotypic spectrum ranging from no clinical signs to severe ectodermal dysplasia. A significant association was found between WNT10A and SAH, and this was mostly observed in individuals with light-coloured hair and regression of the frontoparietal hairline. Notably, the most frequent variant in the cohort [c.682T>A;p.(Phe228Ile)] was in linkage disequilibrium with four common WNT10A variants, all of which have a known association with MPHL. Using UK Biobank data, our analyses showed that c.682T>A;p.(Phe228Ile) and one other variant identified in the SAH cohort are also associated with MPHL, and partially explain the known associations between WNT10A and MPHL. CONCLUSIONS: Our results suggest that WNT10A is associated with SAH and that SAH has a genetic overlap with the common phenotype MPHL. The presumed shared biologic effect of WNT10A variants in SAH and MPHL is a shortening of the anagen phase. Other factors, such as modifier genes and sex, may also play a role in the clinical manifestation of hair phenotypes associated with the WNT10A locus.

Identification and characterisation of a rare MTTP variant underlying hereditary non-alcoholic fatty liver disease.

Background & Aims: Non-alcoholic fatty liver disease (NAFLD) is a complex trait with an estimated prevalence of 25% globally. We aimed to identify the genetic variant underlying a four-generation family with progressive NAFLD leading to cirrhosis, decompensation, and development of hepatocellular carcinoma in the absence of common risk factors such as obesity and type 2 diabetes. Methods: Exome sequencing and genome comparisons were used to identify the likely causal variant. We extensively characterised the clinical phenotype and post-prandial metabolic responses of family members with the identified novel variant in comparison with healthy non-carriers and wild-type patients with NAFLD. Variant-expressing hepatocyte-like cells (HLCs) were derived from human-induced pluripotent stem cells generated from homozygous donor skin fibroblasts and restored to wild-type using CRISPR-Cas9. The phenotype was assessed using imaging, targeted RNA analysis, and molecular expression arrays. Results: We identified a rare causal variant c.1691T>C p.I564T (rs745447480) in MTTP, encoding microsomal triglyceride transfer protein (MTP), associated with progressive NAFLD, unrelated to metabolic syndrome and without characteristic features of abetalipoproteinaemia. HLCs derived from a homozygote donor had significantly lower MTP activity and lower lipoprotein ApoB secretion than wild-type cells, while having similar levels of MTP mRNA and protein. Cytoplasmic triglyceride accumulation in HLCs triggered endoplasmic reticulum stress, secretion of pro-inflammatory mediators, and production of reactive oxygen species. Conclusions: We have identified and characterised a rare causal variant in MTTP, and homozygosity for MTTP p.I564T is associated with progressive NAFLD without any other manifestations of abetalipoproteinaemia. Our findings provide insights into mechanisms driving progressive NAFLD. Impact and Implications: A rare genetic variant in the gene MTTP has been identified as responsible for the development of severe non-alcoholic fatty liver disease in a four-generation family with no typical disease risk factors. A cell line culture created harbouring this variant gene was characterised to understand how this genetic variation leads to a defect in liver cells, which results in accumulation of fat and processes that promote disease. This is now a useful model for studying the disease pathways and to discover new ways to treat common types of fatty liver disease.

Traboulsi syndrome caused by mutations in ASPH: An autosomal recessive disorder with overlapping features of Marfan syndrome.

Traboulsi syndrome, otherwise known as facial dysmorphism, lens dislocation, anterior-segment abnormalities and spontaneous filtering blebs, is an autosomal recessive condition associated with characteristic ocular features including dislocated crystalline lenses, anterior segment abnormalities and in some individuals, non-traumatic conjunctival cysts. There is a distinctive facial appearance which includes flattened malar region with convex nasal ridge. Alterations in the aspartate beta-hydroxylase (ASPH) gene are known to be the cause of the condition. We report seven further individuals from six unrelated families with characteristic ocular and facial features. Five individuals had aortic root dilatation, with childhood onset in some, and one undergoing aortic root repair aged 47 years for severe aortic regurgitation and aortic root dilatation. Interestingly, inguinal hernias were commonly reported. Although some skeletal features were seen, these were not consistent. One of the patients had mild deficiency of factor VII on clotting studies. The ASPH protein hydroxylates specific asparagine- and aspartate-residues in epidermal growth factor (EGF)-domain containing proteins including coagulation factors and associated genes including FBN1. We propose this as an explanation for the overlap in clinical features with Marfan syndrome and conclude that Traboulsi syndrome is an important differential diagnosis. We strongly recommend echocardiography surveillance for patients with Traboulsi syndrome.

Estimating the clinical prevalence of Wilson's disease in the UK.

BACKGROUND & AIMS: The clinical prevalence of Wilson's disease (WD) in the UK remains unknown. The estimated genetic prevalence in the UK, 142/million, is higher than the clinical prevalence (15/million) reported in other European studies. The aim of this study was to estimate the clinical prevalence of WD utilising readily available laboratory and clinical data. METHOD: Patients with WD who attended Nottingham University Hospital NHS Trust (NUH) between 2011 and 2018 were identified using multiple sources of case ascertainment: serum ceruloplasmin, 24-hour urinary copper, 'Wilson' in liver biopsy report, hospital prescription for penicillamine/trientine/zinc and admission coded with ICD-10 Code E83.0 (disorder of copper metabolism). Potential cases were identified using the Leipzig score, diagnosis was confirmed in hospital records and the point prevalence was calculated using the Office for National Statistics mid-2017 population estimates. RESULTS: A total of 1,794 patients were identified from ≥1 source; 19 patients had WD, of whom 11 were from within the study catchment area and alive at the time of point prevalence estimation. Twenty-nine patients had a Leipzig score ≥2 without a diagnosis of WD, but none had WD on screening (n = 16). The overall prevalence of WD was 15.5/million; males 16.9/million and females 14.1/million. CONCLUSION: This is the first UK population-based study to assess the clinical prevalence of WD. The reported clinical prevalence is lower than the UK genetic prevalence, but comparable to the clinical prevalence reported in Europe. The case ascertainment approach used in this study may be cost-effective, and similar practises could be adopted nationally. LAY SUMMARY: Our study estimates the clinical prevalence of Wilson's disease, a rare genetic disorder of copper metabolism, in the UK. The estimated clinical prevalence is this study is markedly lower than the estimated UK genetic prevalence.

Correction to: A meta-analysis of consanguinity and breast cancer.

The original version of this article contained an author name error. Gabiella Jones has been corrected to Gabriela Jones. The original article has been corrected.

The phenotypic spectrum of WWOX-related disorders: 20 additional cases of WOREE syndrome and review of the literature.

PURPOSE: Germline WWOX pathogenic variants have been associated with disorder of sex differentiation (DSD), spinocerebellar ataxia (SCA), and WWOX-related epileptic encephalopathy (WOREE syndrome). We review clinical and molecular data on WWOX-related disorders, further describing WOREE syndrome and phenotype/genotype correlations. METHODS: We report clinical and molecular findings in 20 additional patients from 18 unrelated families with WOREE syndrome and biallelic pathogenic variants in the WWOX gene. Different molecular screening approaches were used (quantitative polymerase chain reaction/multiplex ligation-dependent probe amplification [qPCR/MLPA], array comparative genomic hybridization [array-CGH], Sanger sequencing, epilepsy gene panel, exome sequencing), genome sequencing. RESULTS: Two copy-number variations (CNVs) or two single-nucleotide variations (SNVs) were found respectively in four and nine families, with compound heterozygosity for one SNV and one CNV in five families. Eight novel missense pathogenic variants have been described. By aggregating our patients with all cases reported in the literature, 37 patients from 27 families with WOREE syndrome are known. This review suggests WOREE syndrome is a very severe epileptic encephalopathy characterized by absence of language development and acquisition of walking, early-onset drug-resistant seizures, ophthalmological involvement, and a high likelihood of premature death. The most severe clinical presentation seems to be associated with null genotypes. CONCLUSION: Germline pathogenic variants in WWOX are clearly associated with a severe early-onset epileptic encephalopathy. We report here the largest cohort of individuals with WOREE syndrome.

A meta-analysis of consanguinity and breast cancer.

BACKGROUND: There have been various publications stating that consanguinity both increases and decreases the risk of breast cancer. AIMS: The objective of this study was to determine the impact of consanguinity upon breast cancer. We conducted a systematic review of the literature and meta-analysis. METHODS: Eligible studies were identified on Medline and EMBASE updated to the 19 of September 2017. Studies with sufficient comparative data were included in a meta-analysis. Analyses were carried out using RevMan software. RESULTS: Three comparative studies with a total of 317 individuals with breast cancer and 1459 controls. Reviewing the literature demonstrated conflicting conclusions of the influence of consanguinity upon breast cancer. The meta-analysis showed that there were no statistically significant associations between consanguinity and breast cancer though there was a trend protection from a history of consanguinity. CONCLUSION: Though there is limited literature published on the effects of parental consanguinity, the available data does not demonstrate that it is a risk factor for breast cancer.

An approach to familial lymphoedema.

Lymphoedema is the build-up of lymphatic fluid leading to swelling in the tissues. Most commonly it affects the peripheries. Diagnosis is based on clinical assessment and imaging with lymphoscintigraphy. Treatment is supportive with compression garments, massage, good skin hygiene and prompt use of antibiotics to avoid the complication of cellulitis. Most commonly, lymphoedema occurs as a result of damage to the lymphatic system following surgery, trauma, radiation or infection. However, it can be primary, often associated with a genetic defect that causes disruption to the development of the lymphatic system. Common genetic conditions associated with lymphoedema include Turner syndrome and Noonan syndrome; however, there are numerous others that can be classified based on their clinical presentation and associated features. Herein we discuss how to diagnose and classify the known primary lymphoedema conditions and how best to investigate and manage this group of patients.

Microform holoprosencephaly with bilateral congenital elbow dislocation; increasing the phenotypic spectrum of Steinfeld syndrome.

Steinfeld syndrome (MIM #184705) was first reported in 1982. It is characterised by holoprosencephaly and limb defects, however other anomalies may also be present. Following the initial description, three further cases have been reported in the literature. We report on a 23-year-old girl, with features of microform holoprosencephaly and bilateral congenital elbow dislocation in association with hypoplastic radial heads. She was identified to have a variant in the CDON gene inherited from her father who had ocular hypotelorism, but no other clinical features. We discuss the clinical features of Steinfeld syndrome, and broaden the phenotypic spectrum of this condition. Structural analysis suggests that this variant could lead to destabilisation of binding of CDON with hedgehog proteins. Further work needs to be done to confirm whether mutations in the CDON gene are the cause of Steinfeld syndrome.

Should we offer prenatal testing for 17q12 microdeletion syndrome to all cases with prenatally diagnosed echogenic kidneys? Prenatal findings in two families with 17q12 microdeletion syndrome and review of the literature.

OBJECTIVE: The objective of this study is to report the prenatal ultrasound scan findings in four fetuses from two families postnatally diagnosed with 17q12 microdeletion syndrome on microarray CGH and review the literature. METHODS: We report two families presenting with prenatally detected hyperechogenic kidneys. In family 1, the mother had three pregnancies complicated by anhydramnios with bilateral hyperechogenic kidneys, hyperechogenic enlarged cystic kidneys, and bilateral hyperechogenic kidneys with polyhydramnios respectively. In family 2, prenatal ultrasound scans detected hyperechogenic kidneys. A pubmed search for all reported cases of 17q12 deletion between 2005 and 2015 was performed. All publications were reviewed, and findings summarised. RESULTS: Fourteen publications were deemed suitable for literature review; there was a diagnosis of 17q12 deletion with documented prenatal findings in 25 cases. Prenatal renal anomalies were reported in 88% of these cases. Anomalies were documented from 15 weeks, and most common presentation was hyperechogenic, muticystic, or enlarged kidneys. Both oligohydramnios and polyhydramnios were seen. Postnatal renal ultrasound scan findings were of muticystic or multicystic dysplastic kidney. There did not appear to be correlation of prenatal presentation and severity of renal disease. CONCLUSION: Prenatal testing should be offered to all cases of hyperechogenic kidneys, with unknown cause.