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Background: Addison's disease and X-linked adrenoleukodystrophy (X-ALD) (Addison's-only) are two diseases that need to be identified. Addison's disease is easy to diagnose clinically when only skin and mucosal pigmentation symptoms are present. However, X-ALD (Addison's-only) caused by ABCD1 gene variation is ignored, thus losing the opportunity for early treatment. This study described two patients with initial clinical diagnosis of Addison's disease. However, they rapidly developed neurological symptoms triggered by infection. After further genetic testing, the two patients were diagnosed with X-ALD. Methods: We retrospectively analyzed X-ALD patients admitted to our hospital. Clinical features, laboratory test results, and imaging data were collected. Whole-exome sequencing was used in molecular genetics. Results: Two patients were included in this study. Both of them had significantly increased adrenocorticotropic hormone level and skin and mucosal pigmentation. They were initially clinically diagnosed with Addison's disease and received hydrocortisone treatment. However, both patients developed progressive neurological symptoms following infectious disease. Further brain magnetic resonance imaging was completed, and the results suggested demyelinating lesions. Molecular genetics suggested variations in the ABCD1 gene, which were c.109_110insGCCA (p.C39Pfs*156), c.1394–2 A > C (NM_000033), respectively. Therefore, the two patients were finally diagnosed with X-ALD, whose classification had progressed from X-ALD (Addison's-only) to childhood cerebral adrenoleukodystrophy (CCALD). Moreover, the infection exacerbates the demyelinating lesions and accelerates the onset of neurological symptoms. Neither the two variation sites in this study had been previously reported, which extends the ABCD1 variation spectrum. Conclusions: Patients with only symptoms of adrenal insufficiency cannot be simply clinically diagnosed with Addison's disease. Being alert to the possibility of ABCD1 variation is necessary, and complete genetic testing is needed as soon as possible to identify X-ALD (Addison's-only) early to achieve regular monitoring of the disease and receive treatment early. In addition, infection, as a hit factor, may aggravate demyelinating lesions of CCALD. Thus, patients should be protected from external environmental factors to delay the progression of cerebral adrenoleukodystrophy. [ABSTRACT FROM AUTHOR]

Background: X-linked hypophosphatemia (XLH) is a type of vitamin D-resistant rickets. It is the most common form of it and is related with oral health problems. This study aimed to analyze the OHRQoL of people suffering from XLH and measure physical oral health to confirm or refute evidence of reduced oral health. Methods: The German version of the Oral Health Impact Profile (OHIP-14G), was used to measure OHRQoL. All study participants underwent clinical examination, and oral health was scored using the Physical Oral Health Index (PhOX). Results: A total of 26 people participated in the study, of whom five were male and 21 were female. The average participant age was 40.9 ± 12.8 years. The OHIP-14G score was 14.3 (± 12.1; 95% CI: 9.37. 19.16) points (range 0–44 points). The PhOX score was 77.1 (± 9.9; 95% CI: 73.10—81.13) points (range 61–95 points). Conclusions: The results of this study confirm that oral health and OHRQoL are both reduced in the studied cohort of people affected by XLH. Particular attention should be paid to perfect oral hygiene in people with XLH, as the impaired enamel mineralisation increases the risk of caries and thus also the occurrence of apical infections. [ABSTRACT FROM AUTHOR]

Color vision deficiency is a common X-linked genetic disorder affecting the day-to-day lives of individuals, in which school-aged children's academic performance can be negatively affected. The aim of this study was to evaluate the prevalence and genotypic frequency of congenital color vision defects (CVD), among primary schoolchildren in Adama, Ethiopia. A school-based cross-sectional study design was used. Students were purposively selected based on their ethnicity but were randomly selected from their sections, resulting in a final sample size estimated at 846 schoolchildren who had received informed consent from their families. Data was gathered using the Ishihara color vision test, 38-plate edition. The result of the study revealed that the total prevalence of CVD was much higher (5.6%) among the male children than that of the females, which was only about 1.79%. The prevalence rates of CVD among the targeted ethnic groups were found to be the highest among Amhara (7.45%) > Oromo (5.00%) > Gurage (2.13%) children, respectively, in descending order. 62.76% of the study subjects were homozygous dominant (AA), followed by those with a heterozygous genotype (Aa) (32.51%), and the remaining 4.73% had recessive (aa) genes. [ABSTRACT FROM AUTHOR]

Background and aims: Fabry disease (FD) is an X-linked genetic lysosomal disease, in which a deficit in the alpha-galactosidase A enzyme results in lysosomal build-up of globotriaosylceramide in several organs, causing cardiac, renal and cerebrovascular complications. The aim of this study was to assess the prevalence of papillary muscle hypertrophy (PMH) in patients with FD. Methods: A group of 63 patients with FD and a positive genetic diagnosis were studied and were divided into two groups: one included 24 patients with FD and LVH and another group included 39 patients with FD and without LVH. Papillary muscles were measured from the left parasternal short axis view, defining PMH as a diastolic thickness greater than 11 mm in any diameter. Results: Patients with FD and LVH had a high prevalence of anterolateral PMH (66.6%), and such prevalence was lower for the posteromedial PMH (33.3%). However, patients who had not yet developed LVH had a high prevalence of anterolateral PMH (33.3%). Conclusions: Patients with FD in the pre-clinical stage (without LVH) have a high prevalence of PMH, especially involving the anterolateral papillary muscle. This finding could be an early marker for the development of LVH, allowing to suspect the disease during its early stages, and begin enzyme replacement therapy in the appropriate patients. [ABSTRACT FROM AUTHOR]

Background: Chronic Granulomatous Disease (CGD) is a primary immunodeficiency that causes susceptibility to recurrent fungal and bacterial infections. The CYBB gene encodes gp91phox component of the Phagocytic Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and specifically, X-linked CGD is caused by mutations in the CYBB gene, located on the X chromosome. The aim of the study was to characterize functional and genetic mutations in X-linked CGD. Methods: Functional analysis was conducted on the whole blood of seventeen male individuals who were suspected to have X-linked chronic granulomatous disease (CGD). Flow cytometry was employed to assess the capacity of NADPH oxidase, measuring both H2O2 production and gp91phox protein expression in neutrophils. Additionally, DNA Sanger sequencing was performed for genetic analysis. The pathogenicity of novel mutations was assessed by pathogenicity prediction tools. Result: Among the seventeen patients evaluated, five patients (P1, P2, P3, P4, and P5) displayed impaired H2O2 production by their neutrophils upon stimulation with Phorbol myristate acetate (PMA), accompanied by abnormal gp91phox expression. DNA sequencing of the CYBB gene identified specific mutations in each patient. In P1 and P2 (previously reported cases), a hemizygous missense mutation, c.925G > A/p.E309K was identified. In P3 and P4 (novel cases), hemizygous nonsense mutations, c.216T > A/p.C72X were found. Lastly, in P5 (also a novel case), a hemizygous missense mutation, c.732T > G/p.C244W was detected. These mutations reside in exons 9,3 and 7 of the CYBB gene, respectively. Conclusions: The current study contributes to the understanding of the clinical and genetic spectrum associated with X-linked chronic granulomatous disease (CGD). It highlights the significance of early diagnosis in CGD and emphasizes the importance of lifelong prophylaxis to prevent severe infections. [ABSTRACT FROM AUTHOR]

Background: Duchenne muscular dystrophy (DMD) is an X-linked lethal genetic disorder for which there is no effective treatment. Previous studies have shown that stem cell transplantation into mdx mice can promote muscle regeneration and improve muscle function, however, the specific molecular mechanisms remain unclear. DMD suffers varying degrees of hypoxic damage during disease progression. This study aimed to investigate whether induced pluripotent stem cells (iPSCs) have protective effects against hypoxia-induced skeletal muscle injury. Results: In this study, we co-cultured iPSCs with C2C12 myoblasts using a Transwell nested system and placed them in a DG250 anaerobic workstation for oxygen deprivation for 24 h. We found that iPSCs reduced the levels of lactate dehydrogenase and reactive oxygen species and downregulated the mRNA and protein levels of BAX/BCL2 and LC3II/LC3I in hypoxia-induced C2C12 myoblasts. Meanwhile, iPSCs decreased the mRNA and protein levels of atrogin-1 and MuRF-1 and increased myotube width. Furthermore, iPSCs downregulated the phosphorylation of AMPKα and ULK1 in C2C12 myotubes exposed to hypoxic damage. Conclusions: Our study showed that iPSCs enhanced the resistance of C2C12 myoblasts to hypoxia and inhibited apoptosis and autophagy in the presence of oxidative stress. Further, iPSCs improved hypoxia-induced autophagy and atrophy of C2C12 myotubes through the AMPK/ULK1 pathway. This study may provide a new theoretical basis for the treatment of muscular dystrophy in stem cells. [ABSTRACT FROM AUTHOR]

Background: Contiguous gene deletion syndrome at Xp22.3 resulting in nullisomy in males or Turner syndrome patients typically encompasses the steroid sulfatase gene (STS) and contiguously located other genes expanding the phenotype. In large deletions, that encompass also the Kallmann syndrome 1 gene (KAL1), occasionally infantile hypertrophic pyloric stenosis (IHPS) and congenital anomalies of the kidney and urinary tract (CAKUT) have been reported. Patient presentation: We report on a male newborn with family history in maternal uncle of renal abnormalities and short stature still without ichthyosiform dermatosis. The baby presented CAKUT with kidney failure and progressive vomiting. Renal bicarbonate loss masked hypochloremic and hypokalemic metabolic alkalosis classically present in IHPS and delayed its diagnosis. Antropyloric ultrasound examination and cystourethrography were diagnostic. After Fredet-Ramstedt extramucosal pyloromyotomy feeding and growing was regular and he was discharged home. Comparative whole-genome hybridization detected a maternal inherited interstitial deletion of 1.56 Mb on Xp22.31(6,552,712_8,115,153) × 0 involving the STS gene, but not the KAL1 gene. Conclusions: Aberrant cholesterol sulfate storage due to STS deletion as the underlying pathomechanism is not limited to oculocutaneous phenotypes but could also lead to co-occurrence of both IHPS and kidney abnormalities, as we report. Thus, although these two latter pathologies have a high incidence in the neonatal age, their simultaneous association in our patient is resembling not a chance but a real correlation expanding the clinical spectrum associated with Xp22.31 deletions. [ABSTRACT FROM AUTHOR]

Background: Contiguous gene deletion syndromes are rare genomic disorders caused by deletion of large segments of DNA resulting in co-occurrence of apparently unrelated multiple clinical phenotypes. We report a boy with contiguous gene deletion involving Xp21 genomic location. Case presentation: A Sri Lankan boy with developmental delay and failure to thrive first presented at three years of age with hypovolaemia, hyperpigmentation and drowsiness. Investigations done at that time revealed hypoglycaemia, hyponatraemia, hyperkalaemia, low cortisol, low aldosterone, high ACTH and low 17-hydroxyprogesterone. He was diagnosed to have primary adrenal insufficiency. During follow-up at five years, he was noted to have progressive difficulty in walking, waddling gait, hypotonia, calf hypertrophy and positive Gower's sign. His creatine kinase was very high, and the electromyogram showed myopathy. Genetic analysis revealed hemizygous deletion involving the final 35 exons of the dystrophin gene confirming the diagnosis of Duchenne muscular dystrophy. Further investigations revealed pseudohypertriglyceridemia, large glycerol peak on urine organic acid analysis and hemizygous deletion of the glycerol kinase gene confirming glycerol kinase deficiency. Based on the presence of Duchenne muscular dystrophy, glycerol kinase deficiency and probable congenital adrenal hypoplasia along with genetic confirmation of deletions involving dystrophin and glycerol kinase genes, the diagnosis of Xp21 contiguous gene deletion syndrome was made. Conclusions: We report a child with contiguous gene deletion syndrome who was initially diagnosed as having isolated primary adrenal insufficiency probably due to congenital adrenal hypoplasia. Later he was confirmed to have Duchenne muscular dystrophy and glycerol kinase deficiency, as well. This case report highlights the importance of pre-emptive evaluation and identification of genetic defects when patients present with seemingly unrelated diseases that could aid in accurate diagnoses of contiguous gene deletion syndromes. [ABSTRACT FROM AUTHOR]

Background: Most patients with congenital adrenal hypoplasia (AHC) develop symptoms during infantile and juvenile periods, with varying clinical manifestations. AHC is a disease that is easily misdiagnosed as Addison's disease or congenital adrenal hyperplasia (CAH). There was also a significant time difference between the age at which patients developed symptoms and the age at which they were diagnosed with AHC. Most patients showed early symptoms during infantile and juvenile periods, but were diagnosed with AHC many years later. Case presentation: We are currently reporting a male patient who developed systemic pigmentation at age 2 and was initially diagnosed with Addison's disease. At 22 years of age, he experienced a slipped capital femoral epiphysis (SCFE), a disease mostly seen in adolescents aged 8–15 years, an important cause of which is endocrine disorder. Testes evaluated using color Doppler Ultrasonography suggested microcalcifications. Further genetic testing and auxiliary examinations revealed that the patient had hypogonadotropic hypogonadism (HH) and DAX-1 gene disorders, at which time he was diagnosed with AHC complicated by HH. He was given hormone replacement therapy, followed by regular outpatient review to adjust the medication. Conclusions: The typical early symptoms of AHC are hyperpigmentation and ion disturbance during infantile and juvenile periods, while few patients with AHC develop puberty disorders as early symptoms. AHC is prone to being misdiagnosed as Addison's disease, and then gradually develops the symptoms of HH in adolescence. The definitive diagnosis of AHC ultimately is based on the patient's clinical presentation, laboratory results and genetic testing results. [ABSTRACT FROM AUTHOR]

Background: X-linked hypophosphatemia (XLH) is a hereditary rare disease caused by loss-of-function mutations in PHEX gene leading tohypophosphatemia and high renal loss of phosphate. Rickets and growth retardation are the major manifestations of XLH in children, but there is a broad phenotypic variability. Few publications have reported large series of patients. Current data on the clinical spectrum of the disease, the correlation with the underlying gene mutations, and the long-term outcome of patients on conventional treatment are needed, particularly because of the recent availability of new specific medications to treat XLH.Results: The RenalTube database was used to retrospectively analyze 48 Spanish patients (15 men) from 39 different families, ranging from 3 months to 8 years and 2 months of age at the time of diagnosis (median age of 2.0 years), and with XLH confirmed by genetic analysis. Bone deformities, radiological signs of active rickets and growth retardation were the most common findings at diagnosis. Mean (± SEM) height was - 1.89 ± 0.19 SDS and 55% (22/40) of patients had height SDS below-2. All cases had hypophosphatemia, serum phosphate being - 2.81 ± 0.11 SDS. Clinical manifestations and severity of the disease were similar in both genders. No genotype-phenotype correlation was found. Conventional treatment did not attenuate growth retardation after a median follow up of 7.42 years (IQR = 11.26; n = 26 patients) and failed to normalize serum concentrations of phosphate. Eleven patients had mild hyperparathyroidism and 8 patients nephrocalcinosis.Conclusions: This study shows that growth retardation and rickets were the most prevalent clinical manifestations at diagnosis in a large series of Spanish pediatric patients with XLH confirmed by mutations in the PHEX gene. Traditional treatment with phosphate and vitamin D supplements did not improve height or corrected hypophosphatemia and was associated with a risk of hyperparathyroidism and nephrocalcinosis. The severity of the disease was similar in males and females. [ABSTRACT FROM AUTHOR]

Background: DAX1 mutations are related to the X-linked form of adrenal hypoplasia congenita (AHC) in infancy and to hypogonadotropic hypogonadism (HH) in puberty. We report a male patient affected by X-linked AHC who presented with central diabetes insipidus and schwannoma in adulthood, which has not been described in association with AHC. Case presentation: A 36-day-old male infant who presented with severe dehydration was admitted to the intensive care unit. His laboratory findings showed hyponatremia, hyperkalemia, hypoglycemia, and metabolic acidosis. After hormonal evaluation, he was diagnosed with adrenal insufficiency, and he recovered after treatment with hydrocortisone and a mineralocorticoid. He continued to take hydrocortisone and the mineralocorticoid after discharge. At the age of 17, he did not show any signs of puberty. On the basis of a GnRH test, a diagnosis of HH was made. At the age of 24, he was hospitalized with thirst, polydipsia and polyuria. He underwent a water deprivation test for polydipsia and was diagnosed with central diabetes insipidus. By quantitative polymerase chain reaction analysis, we identified a hemizygous frameshift mutation in DAX1 (c.543delA). Conclusions: We suggest that DAX1 mutations affect a wider variety of endocrine organs than previously known, including the posterior pituitary gland. [ABSTRACT FROM AUTHOR]

Background: During the evolution of mammalian sex chromosomes, the degeneration of Y-linked homologs has led to a dosage imbalance between X-linked and autosomal genes. The evolutionary resolution to such dosage imbalance, as hypothesized by Susumu Ohno fifty years ago, should be doubling the expression of X-linked genes. Recent studies have nevertheless shown that the X to autosome expression ratio equals ~ 1 in haploid human parthenogenetic embryonic stem (pES) cells and ~ 0.5 in diploid pES cells, suggesting no doubled expression for X-linked genes and refuting Ohno's hypothesis. Results: Here, by reanalyzing an RNA-seq-based single-cell transcriptome dataset of human embryos, we found that from the 8-cell stage until the time-point just prior to implantation, the expression levels of X-linked genes are not two-fold upregulated in male cells and gradually decrease from two-fold in female cells. Additional analyses of gene expression noise further suggest that the dosage sensitivity of X-linked genes is weaker than that of autosomal genes in differentiated female cells, which contradicts a key assumption in Ohno's hypothesis, that most X-linked genes are dosage sensitive. Moreover, the dosage-sensitive housekeeping genes are preferentially located on autosomes, implying selection against X-linkage for dosage-sensitive genes. Conclusions: We observed dosage imbalance between X-linked and autosomal genes, as well as relatively high expression noise from X-linked genes. These results collectively suggest that X-linked genes are less dosage sensitive than autosomal genes, putting one primary assumption of Ohno's hypothesis in question. [ABSTRACT FROM AUTHOR]

Background: Claes-Jensen syndrome is an X-linked inherited intellectual disability caused by mutations in the KDM5C gene. Kdm5c is a histone lysine demethylase involved in histone modifications and chromatin remodeling. Males with hemizygous mutations in KDM5C present with intellectual disability and facial dysmorphism, while most heterozygous female carriers are asymptomatic. We hypothesized that loss of Kdm5c function may influence other components of the epigenomic machinery including DNA methylation in affected patients. Results: Genome-wide DNA methylation analysis of 7 male patients affected with Claes-Jensen syndrome and 56 age- and sex-matched controls identified a specific DNA methylation defect (epi-signature) in the peripheral blood of these patients, including 1769 individual CpGs and 9 genomic regions. Six healthy female carriers showed less pronounced but distinctive changes in the same regions enabling their differentiation from both patients and controls. Highly specific computational model using the most significant methylation changes demonstrated 100% accuracy in differentiating patients, carriers, and controls in the training cohort, which was confirmed on a separate cohort of patients and carriers. The 100% specificity of this unique epi-signature was further confirmed on additional 500 unaffected controls and 600 patients with intellectual disability and developmental delay, including other patient cohorts with previously described epi-signatures. Conclusion: Peripheral blood epi-signature in Claes-Jensen syndrome can be used for molecular diagnosis and carrier identification and assist with interpretation of genetic variants of unknown clinical significance in the KDM5C gene. [ABSTRACT FROM AUTHOR]

Background: Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are X-linked recessive disorders caused by mutations in the DMD gene. The aim of this study was to predict the effect of gene mutations on the dystrophin protein and study its impact on clinical phenotype. Methods: In this study, 415 clinically diagnosed patients were tested for mutations by Multiplex ligation dependent probe amplification (MLPA). Muscle biopsy was performed in 34 patients with negative MLPA. Phenotype-genotype correlation was done using PROVEAN, hydrophobicity and eDystrophin analysis. We have utilized bioinformatics tools in order to evaluate the observed mutations both at the level of primary as well as secondary structure. Results: Mutations were identified in 75.42% cases, of which there were deletions in 91.6% and duplications in 8. 30%. As per the reading frame rule, 84.6% out-of frame and 15.3% in-frame mutations were noted. Exon 50 was the most frequently deleted exon and the exon 45-52 region was the hot-spot for deletions in this cohort. There was no correlation noted between age of onset or creatine kinase (CK) values with extent of gene mutation. The PROVEAN analysis showed a deleterious effect in 94.5% cases and a neutral effect in 5.09% cases. Mutations in exon 45-54 (out of frame) and exon 46-54 (in-frame) regions in the central rod domain of dystrophin showed more negative scores compared to other domains in the present study. Hydrophobicity profile analysis showed that the hydrophobic regions I & III were equally affected. Analysis of deletions in hinge III hydrophobic region by the eDystrophin programme also predicted a hybrid repeat seen to be associated with a BMD like disease progression, thus making the hinge III region relatively tolerant to mutations. Conclusions: We found that, while the predictions made by the software utilized might have overall significance, the results were not convincing on a case by case basis. This reflects the inadequacy of the currently available tools and also underlines the possible inadequacy of MLPA to detect other minor mutations that might enhance or suppress the effect of the primary mutation in this large gene. Next Generation Sequencing or targeted Sanger sequencing on a case by case basis might improve phenotype- genotype correlation. [ABSTRACT FROM AUTHOR]

Background: The study is aimed to describe a novel strategy that increases the accuracy and reliability of PGD in patients using sperm donation by pre-selecting the donor whose haplotype does not overlap the carrier's one. Methods: A panel of 4-9 informative polymorphic markers, flanking the mutation in carriers of autosomal dominant/X-linked disorders, was tested in DNA of sperm donors before PGD. Whenever the lengths of donors' repeats overlapped those of the women, additional donors' DNA samples were analyzed. The donor that demonstrated the minimal overlapping with the patient was selected for IVF. Results: In 8 out of 17 carriers the markers of the initially chosen donors overlapped the patients' alleles and 2-8 additional sperm donors for each patient were haplotyped. The selection of additional sperm donors increased the number of informative markers and reduced misdiagnosis risk from 6.00% ± 7.48 to 0.48% ±0.68. The PGD results were confirmed and no misdiagnosis was detected. Conclusions: Our study demonstrates that pre-selecting a sperm donor whose haplotype has minimal overlapping with the female's haplotype, is critical for reducing the misdiagnosis risk and ensuring a reliable PGD. This strategy may contribute to prevent the transmission of affected IVF-PGD embryos using a simple and economical procedure. Trial registration: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. DNA testing of donors was approved by the institutional Helsinki committee (registration number 319-08TLV, 2008). The present study was approved by the institutional Helsinki committee (registration number 0385-13TLV, 2013). [ABSTRACT FROM AUTHOR]

Background: X-linked Retinoschisis (XLRS) is one of the most common macular degenerations in young males, with a worldwide prevalence ranging from 1:5000 to 1:20000. Clinical diagnosis of XLRS can be challenging due to the highly variable phenotypic presentation and limited correlation has been identified between mutation type and disease severity or progression.Case Presentation: We report the atypical early onset of XLRS in 3-month-old monozygotic twins. Fundus examination was characterized by severe bullous retinal schisis with pre-retinal and intraretinal haemorrhages. Molecular genetic analysis of the RS1 was performed and the c.288G > A (p. Trp96Ter) mutation was detected in both patients.Conclusions: Early onset XLRS is associated with a more progressive form of the disease, characterized by large bullous peripheral schisis involving the posterior pole, vascular abnormalities and haemorrhages. The availability of specific technology permitted detailed imaging of the clinical picture of unusual cases of XLRS. The possible relevance of modifying genes should be taken into consideration for the future development of XLRS gene therapy. [ABSTRACT FROM AUTHOR]

Background: Barth syndrome (BTHS) is a rare X-linked recessive disease characterized by cardiomyopathy, neutropenia, skeletal myopathy and growth delay. Early diagnosis and appropriate treatment may improve the prognosis of this disease. The purpose of this study is to determine the role of targeted next-generation sequencing (NGS) in the early diagnosis of BTHS in children with cardiomyopathy.Methods: During the period between 2012 and 2015, a gene panel-based NGS approach was used to search for potentially disease-causing genetic variants in all patients referred to our institution with a clinical diagnosis of primary cardiomyopathy. NGS was performed using the Illumina sequencing system.Results: A total of 180 Chinese pediatric patients (114 males and 66 females) diagnosed with primary cardiomyopathy were enrolled in this study. TAZ mutations were identified in four of the male index patients, including two novel mutations (c.527A > G, p.H176R and c.134_136delinsCC, p.H45PfsX38). All four probands and two additional affected male family members were born at full term with a median birth weight of 2350 g (range, 2000-2850 g). The median age at diagnosis of cardiomyopathy was 3.0 months (range, 1.0-20.0 months). The baseline echocardiography revealed prominent dilation and trabeculations of the left ventricle with impaired systolic function in the six patients, four of which fulfilled the diagnostic criteria of left ventricular noncompaction. Other aspects of their clinical presentations included hypotonia (6/6), growth delay (6/6), neutropenia (3/6) and 3-methylglutaconic aciduria (4/5). Five patients died at a median age of 7.5 months (range, 7.0-12.0 months). The cause of death was heart failure associated with infection in three patients and cardiac arrhythmia in two patients. The remaining one patient survived beyond infancy but had fallen into a persistent vegetative state after suffering from cardiac arrest.Conclusions: This is the first report of systematic mutation screening of TAZ in a large cohort of pediatric patients with primary cardiomyopathy using the NGS approach. TAZ mutations were found in 4/114 (3.5%) male patients with primary cardiomyopathy. Our findings indicate that the inclusion of TAZ gene testing in cardiomyopathy genetic testing panels may contribute to the early diagnosis of BTHS. [ABSTRACT FROM AUTHOR]

Background: The X-linked condition "Aarskog-Scott syndrome (AAS)" causes a characteristic combination of short stature, facial, genital and skeletal anomalies. Studies elucidated a causative link between AAS and mutations in the FGD1 gene, which encodes a Rho/Rac guanine exchange factor. FGD1 is involved in regulating signaling pathways that control cytoskeleton organization and embryogenesis.Case Presentation: FGD1 was studied in an Emirati family with two cases of AAS using PCR amplification and direct sequencing of the entire coding region of the gene. Various in silico tools were also used to predict the functional consequences of FGD1 mutations. In the reported family, two brothers harbor a novel hemizygous mutation in FGD1 c.53del (p.Pro18Argfs*106) for which the mother is heterozygous. This frameshift deletion, being close to N-terminus of FGD1, is predicted to shift the reading frame in a way that it translates to 105 erroneous amino acids followed by a premature stop codon at position 106. Full molecular and clinical accounts about the variant are given so as to expand molecular and phenotypical knowledge about this disorder.Conclusions: A novel variant in FGD1 was found in an Emirati family with two brothers suffering from AAS. The variant is predicted to be a null mutation, and this is the first report of its kind from the United Arab Emirates. [ABSTRACT FROM AUTHOR]

Background: Wiskott-Aldrich syndrome is a rare X-linked disorder characterized by microthrombocytopenia, eczema, and recurrent infections. It is caused by mutations of the WAS gene. Microthrombocytopenia has been regarded as the key criteria in diagnosing this rare condition. However, in this case report, we describe a case of Wiskott-Aldrich syndrome with normal platelet size.Case Presentation: We report the case of a 9-month-old Malay boy who presented with persistent thrombocytopenia from birth. Serial blood investigations at birth showed he had normal platelet size. His family history revealed two early neonatal deaths in maternal uncles. Spontaneous bleeding was only seen at the age of 3 months. He was initially treated for immune thrombocytopenic purpura and was started on intravenously administered immunoglobulin. His clinical deterioration and poor response to the immunoglobulin raised suspicion for a different underlying pathology. Molecular analysis of the WAS gene revealed a missense mutation in exon 10. His parents refused further interventions and defaulted on subsequent follow-up appointments.Conclusions: A diagnosis of Wiskott-Aldrich syndrome should be considered in any male infant who presents with early onset thrombocytopenia despite an absence of small platelet size, a characteristic feature of Wiskott-Aldrich syndrome. [ABSTRACT FROM AUTHOR]

Background: Brain-expressed X-linked (BEX) 4 is a member of BEX family. The functional role of BEX4 in oral squamous cell carcinoma (OSCC) remains unknown. Methods: Expression level of BEX family members (BEX1-5) in OSCC tissues and the paired normal epithelial were examined. Functions of epigenetic changes (DNA methylation and histone modifications) on BEX4 suppression in OSCC were examined by zebularine and trichostatin A (TSA) treatment on OSCC cell lines. Lentivector containing full-length BEX4 was used to generate OSCC cell lines with stable BEX4 expression. Effects of BEX4 expression on OSCC proliferation were monitored with xCELLigence RTCA real-time cell analyzer. BEX4-overexpressing CAL27 was implanted into nude mice to evaluate the effects on tumor growth in vivo. The signaling pathways regulated by BEX4 in OSCC was explored using human whole-transcript expression microarray. Results: Among the 5 BEX family members, BEX1 and BEX4 showed significant down-regulation in OSCC (P < 0.001). BEX3, in comparison, was overexpressed in the primary tumor. BEX4 expression in OSCC cell lines was re-activated after zebularine and TSA treatment. High BEX4 expression could suppress proliferation of OSCC in vitro. Subcutaneous tumor volume of BEX4-overexpressing CAL27 was remarkably reduced in nude mice. Microarray experiment showed that S100A family members (S100A7, S100A7A, S100A8, S100A9 & S100A12) might be the downstream targets of BEX4 in OSCC. Conclusions: BEX4 functions as tumor suppressor by inhibiting proliferation and growth of oral cancer. Decreased BEX4 contributes to the increased proliferative propensity of OSCC. [ABSTRACT FROM AUTHOR]

Background: X-linked retinoschisis is a recessively inherited retinal degeneration. Clinical diagnosis can be challenging due to the highly variable phenotypic presentation. Also, clinical diagnostic tests may be normal at early stages of this condition. Therefore, genetic diagnosis has become a priceless tool in the management of this disease. Case presentation: We present a case of a 17-year-old caucasian male with foveal and peripheral schisis, along with Mizuo-Nakamura phenomenon. RS1 sequencing led to the discovery of an in-frame deletion not previously described in the literature. Conclusions: Genetic deletions causative of X-linked retinoschisis are quite rare, since more than 80 % are caused by misssense mutations. In this particular case, its pathological effect comes from affecting a key element of the retinoschisin, the discoidin domain. [ABSTRACT FROM AUTHOR]

Background: X-linked adrenoleukodystrophy (X-ALD; OMIM: 300100) is the most common peroxisomal disease caused by mutations in the ATP-binding cassette, sub-family D member 1 gene or ABCD1 (geneID: 215), the coding gene for the adrenoleukodystrophy protein (ALDP), which is an ATP-binding transport protein associated to an active transport of very long chain fatty acids (VLCFAs). Dysfunction of ALDP induces an accumulation of VLCFAs in all tissues leading to a neurodegenerative disorder that involves the nervous system white matter.Case Presentation: In our case report, magnetic resonance imaging (MRI) as well as the high levels of VLCFAs prompted the diagnosis the X-ALD. Molecular analysis of ABCD1 gene have shown a pathogenic homozygous nonsense mutation (c.1677C > G; p.(Tyr559*)) in exon 7.Conclusion: Thus, we identified here a novel mutation in the ABCD1 gene in a Moroccan patient causing X-linked adrenoleukodystrophy. [ABSTRACT FROM AUTHOR]

Background: The methyl-CpG Binding Protein two gene (MECP2) encodes a multifunctional protein comprising two isoforms involved in nuclear organization and regulation of splicing and mRNA template activity. This gene is normally expressed in all tissues, with a higher expression level in the brain during neuronal maturation. Loss of MECP2 function is the primary cause of Rett syndrome (RTT) in humans, a dominant, X-linked disorder dramatically affecting neural and motor development. Results: We investigated the molecular evolution of MECP2 in several primate taxa including 36 species in 16 genera of neotropical (platyrrhine) primates. The coding region of the MECP2_e2 isoform showed a high level of evolutionary conservation among humans and other primates, with amino acid substitutions in 14 codons and one in-frame insertion of a single serine codon, between codons 357 and 358, in Ateles paniscus. Most substitutions occurred in noncritical regions of MECP2 and the majority of the algorithms used for analyzing selection did not provide evidence of positive selection. Conversely, we found 48 sites under negative selection in different regions, 23 of which were consistently found by three different algorithms. Similar to an inverted Alu insert found previously in a lesser ape at a parallel location, one Alu insertion of approximately 300 bp in Cebus and Sapajus was found in intron 3. Phylogenetic reconstruction of the intron 3 data provided a topology that was coincident with the consensus arrangement of the primate taxa. RNAseq data in the neotropical primate Callimico goeldii revealed a novel transcript consisting of a noncontinuous region of the human-homologous intron 2 in this species; this transcript accounted for two putative polypeptides. Conclusions: Despite the remarkable evolutionary conservation of MECP2, one in-frame codon insertion was observed in A. paniscus, and one region of intron 3 was affected by a trans-specific Alu retrotransposition in two neotropical primate genera. Moreover, identification of novel MECP2 transcripts in Callimico suggests that part of a homologous human intronic region might be expressed, and that the potential open reading frame in this region might be a subject of interest in RTT patients who carry an apparently normal MECP2 sequence. [ABSTRACT FROM AUTHOR]

Dent disease is a rare X-linked tubulopathy with low molecular weight proteinuria, hypercalciuria, nephrolithiasis, nephrocalcinosis and progressive renal failure. We describe the case of a 9-year-old boy who presented with nephrotic-range albuminuria at the age of 3 years. In the absence of a clear diagnosis, a renal biopsy was performed at 4 years, which revealed minimal change disease. Due to the presence of low molecular weight proteinuria, even in the absence of hypercalciuria, a diagnosis of Dent disease was considered. While there were no mutations in the CLCN5 gene, the diagnosis was confirmed by the presence of a missense mutation (p.Arg318Cys) in the OCRL gene. Conclusion: Given the large phenotypic variability of the disease and based on our experience, we believe that children with low molecular weight proteinuria, even without hypercalciuria, should be investigated for Dent disease. [ABSTRACT FROM AUTHOR]

Background: Mutations in the POU3F4 gene cause X-linked deafness type 3 (DFN3), which is characterized by inner ear anomalies. Methods: Three Turkish, one Ecuadorian, and one Nigerian families were included based on either inner ear anomalies detected in probands or X-linked family histories. Exome sequencing and/or Sanger sequencing were performed in order to identify the causative DNA variants in these families. Results: Four novel, c.707A>C (p.(Glu236Ala)), c.772delG (p.(Glu258ArgfsX30)), c.902C>T (p.(Pro301Leu)), c.987T>C (p.(Ile308Thr)), and one previously reported mutation c.346delG (p.(Ala116ProfsX26)) in POU3F4, were identified. All mutations identified are predicted to affect the POU-specific or POU homeo domains of the protein and co-segregated with deafness in all families. Conclusions: Expanding the spectrum of POU3F4 mutations in different populations along with their associated phenotypes provides better understanding of their clinical importance and will be helpful in clinical evaluation and counseling of the affected individuals. [ABSTRACT FROM AUTHOR]

Background: Our genomewide studies support targeted testing the most frequent genetic diseases by patient category: (1) pregnant patients, (2) at-risk conceptuses, (3) affected children, and (4) abnormal adults. This approach not only identifies most reported disease causing sequences accurately, but also minimizes incorrectly identified additional disease causing loci. Methods: Diseases were grouped in descending order of occurrence from four data sets: (1) GeneTests 534 listed population prevalences, (2) 4129 high risk prenatal karyotypes, (3) 1265 affected patient microarrays, and (4) reanalysis of 25,452 asymptomatic patient results screened prenatally for 108 genetic diseases. These most frequent diseases are categorized by transmission: (A) autosomal recessive, (B) X-linked, (C) autosomal dominant, (D) microscopic chromosome rearrangements, (E) submicroscopic copy number changes, and (F) frequent ethnic diseases. Results: Among affected and carrier patients worldwide, most reported mutant genes would be identified correctly according to one of four patient categories from at-risk couples with <64 tested genes to affected adults with 314 tested loci. Three clinically reported patient series confirmed this approach. First, only 54 targeted chromosomal sites would have detected all 938 microscopically visible unbalanced karyotypes among 4129 karyotyped POC, CVS, and amniocentesis samples. Second, 37 of 48 reported aneuploid regions were found among our 1265 clinical microarrays confirming the locations of 8 schizophrenia loci and 20 aneuploidies altering intellectual ability, while also identifying 9 of the most frequent deletion syndromes. Third, testing 15 frequent genes would have identified 124 couples with a 1 in 4 risk of a fetus with a recessive disease compared to the 127 couples identified by testing all 108 genes, while testing all mutations in 15 genes could have identified more couples. Conclusion: Testing the most frequent disease causing abnormalities in 1 of 8 reported disease loci [~1 of 84 total genes] will identify ~7 of 8 reported abnormal Caucasian newborn genotypes. This would eliminate ~8 to 10 of ~10 Caucasian newborn gene sequences selected as abnormal that are actually normal variants identified when testing all ~2500 diseases looking for the remaining 1 of 8 disease causing genes. This approach enables more accurate testing within available laboratory and reimbursement resources. [ABSTRACT FROM AUTHOR]

Background Phosphoribosyl pyrophosphate synthetase (PRS) I deficiency is a rare medical condition caused by missense mutations in PRPS1 that lead to three different phenotypes: Arts Syndrome (MIM 301835), X-linked Charcot-Marie-Tooth (CMTX5, MIM 311070) or X linked non-syndromic sensorineural deafness (DFN2, MIM 304500). All three are X-linked recessively inherited and males affected display variable degree of central and peripheral neuropathy. We applied whole exome sequencing to a three-generation family with optic atrophy followed by retinitis pigmentosa (RP) in all three cases, and ataxia, progressive peripheral neuropathy and hearing loss with variable presentation. Methods Whole exome sequencing was performed in two affecteds and one unaffected member of the family. Sanger sequencing was used to validate and segregate the 12 candidate mutations in the family and to confirm the absence of the novel variant in PRPS1 in 191 controls. The pathogenic role of the novel mutation in PRPS1 was assessed in silico and confirmed by enzymatic determination of PRS activity, mRNA expression and sequencing, and Xchromosome inactivation. Results A novel missense mutation was identified in PRPS1 in the affected females. Age of onset, presentation and severity of the phenotype are highly variable in the family: both the proband and her mother have neurological and ophthalmological symptoms, whereas the phenotype of the affected sister is milder and currently confined to the eye. Moreover, only the proband displayed a complete lack of expression of the wild type allele in leukocytes that seems to correlate with the degree of PRS deficiency and the severity of the phenotype. Interestingly, optic atrophy and RP are the only common manifestations to all three females and the only phenotype correlating with the degree of enzyme deficiency. Conclusions These results are in line with recent evidence of the existence of intermediate phenotypes in PRS-I deficiency syndromes and demonstrate that females can exhibit a disease phenotype as severe and complex as their male counterparts. [ABSTRACT FROM AUTHOR]

The syndrome of immune dysregulation, polyendocrinopathy, enteropathy, X linked (IPEX) is a rare disorder caused by mutations in the FOXP3 gene. Diarrhea, diabetes and dermatitis are the hallmark of the disease, with a typical onset within the first months of life. We describe the case of a twelve-year old male affected by a very late-onset IPEX with intractable enteropathy, which markedly improved after starting Sirolimus as second-line treatment. This case suggests that IPEX should always be considered in the differential diagnosis of watery intractable diarrhea, despite its unusual onset. [ABSTRACT FROM AUTHOR]

Background X-linked periventricular nodular heterotopia is a disorder of neuronal migration resulting from mutations in the filamin A gene. This is an X-linked dominant condition where most affected patients are female and present with seizures. Extra-cerebral features such as cardiac abnormalities and thrombocytopenia have also been documented. Loss of function mutations in filamin A are predicted to result in prenatal lethality in males. Somatic mosaicism and mutations that lead to partial loss of function of the protein are hypothesized to explain viability of males reported in the literature. We report the first case of germline mosaicism involving a loss of function mutation in filamin A in a family where brain MRI, clinical exam, and mutation analysis is normal in both biological parents. Case presentation The index patient, a 39 year old female with normal development, had her first seizure at 24 years with no evidence of any precipitating factors. Brain MRI shows bilateral periventricular nodular heterotopia. She has thrombocytopenia and an echocardiogram at age 32 years revealed a mildly dilated aortic root and ascending aorta with mild aortic regurgitation. The second patient, the 36 year old younger sister of the index case, is currently healthy with no evidence of seizures or cardiac abnormalities. Her brain MRI is consistent with bilateral periventricular nodular heterotopia. The mother is healthy at 57 years of age with a normal brain MRI. The father is healthy at 59 years of age with a normal brain MRI. DNA sequencing of lymphocyte extracted DNA from the two sisters shows a c.2002C > T transition in exon 13 of filamin A resulting in a p.Gln668Ter mutation. This nonsense mutation was not detected in peripheral blood lymphocytes from the unaffected parents. Conclusion This report provides evidence for germline mosaicism in filamin A-associated periventricular nodular heterotopia. This case must now be considered when providing genetic counseling to families where a proband presents as an isolated case and parental investigations are unremarkable. [ABSTRACT FROM AUTHOR]

Background Segmental Xp22.2 monosomy or a heterozygous HCCS mutation is associated with the microphthalmia with linear skin defects (MLS) or MIDAS (microphthalmia, dermal aplasia, and sclerocornea) syndrome, an X-linked disorder with male lethality. HCCS encodes the holocytochrome c-type synthase involved in mitochondrial oxidative phosphorylation (OXPHOS) and programmed cell death. Methods We characterized the X-chromosomal abnormality encompassing HCCS or an intragenic mutation in this gene in six new female patients with an MLS phenotype by cytogenetic analysis, fluorescence in situ hybridization, sequencing, and quantitative real-time PCR. The X chromosome inactivation (XCI) pattern was determined and clinical data of the patients were reviewed. Results Two terminal Xp deletions of ⩾11.2 Mb, two submicroscopic copy number losses, one of ∼850 kb and one of ⩾3 Mb, all covering HCCS, 1 nonsense, and one mosaic 2-bp deletion in HCCS are reported. All females had a completely (>98:2) or slightly skewed (82:18) XCI pattern. The most consistent clinical features were microphthalmia/anophthalmia and sclerocornea/corneal opacity in all patients and congenital linear skin defects in 4/6. Additional manifestations included various ocular anomalies, cardiac defects, brain imaging abnormalities, microcephaly, postnatal growth retardation, and facial dysmorphism. However, no obvious clinical sign was observed in three female carriers who were relatives of one patient. Conclusion Our findings showed a wide phenotypic spectrum ranging from asymptomatic females with an HCCS mutation to patients with a neonatal lethal MLS form. Somatic mosaicism and the different ability of embryonic cells to cope with an OXPHOS defect and/or enhanced cell death upon HCCS deficiency likely underlie the great variability in phenotypes. [ABSTRACT FROM AUTHOR]

Background Rett syndrome (RTT) is an X-linked neurodevelopmental disease affecting predominantly females caused by MECP2 mutations. Although RTT is classically considered a monogenic disease, a stable proportion of patients, who do not exhibit MECP2 sequence variations, does exist. Here, we have attempted at uncovering genetic causes underlying the disorder in mutation-negative cases by whole genome analysis using array comparative genomic hybridization (CGH) and a bioinformatic approach. Results Using BAC and oligonucleotide array CGH, 39 patients from RTT Russian cohort (in total, 354 RTT patients), who did not bear intragenic MECP2 mutations, were studied. Among the individuals studied, 12 patients were those with classic RTT and 27 were those with atypical RTT. We have detected five 99.4 kb deletions in chromosome Xq28 affecting MECP2 associated with mild manifestations of classic RTT and five deletions encompassing MECP2 spanning 502.428 kb (three cases), 539.545 kb (one case) and 877.444 kb (one case) associated with mild atypical RTT. A case has demonstrated somatic mosaicism. Regardless of RTT type and deletion size, all the cases exhibited mild phenotypes. Conclusions Our data indicate for the first time that no fewer than 25% of RTT cases without detectable MECP2 mutations are caused by Xq28 microdeletions. Furthermore, Xq28 (MECP2) deletions are likely to cause mild subtypes of the disease, which can manifest as both classical and atypical RTT. [ABSTRACT FROM AUTHOR]

Fabry disease is a rare X-linked hereditary disease caused by mutations in the AGAL gene encoding the lysosomal enzyme alpha-galactosidase A. Enzyme replacement therapy (ERT) is the current cornerstone of Fabry disease management. Involvement of kidney, heart and the central nervous system shortens life span, and fibrosis of these organs is a hallmark of the disease. Fibrosis was initially thought to result from tissue ischemia secondary to endothelial accumulation of glycosphingolipids in the microvasculature. However, despite ready clearance of endothelial deposits, ERT is less effective in patients who have already developed fibrosis. Several potential explanations of this clinical observation may impact on the future management of Fabry disease. Alternative molecular pathways linking glycosphingolipids and fibrosis may be operative; tissue injury may recruit secondary molecular mediators of fibrosis that are unresponsive to ERT, or fibrosis may represent irreversible tissue injury that limits the therapeutic response to ERT. We provide an overview of Fabry disease, with a focus on the assessment of fibrosis, the clinical consequences of fibrosis, and recent advances in understanding the cellular and molecular mechanisms of fibrosis that may suggest novel therapeutic approaches to Fabry disease. [ABSTRACT FROM AUTHOR]

Background: Global developmental delay and mental retardation are associated with X-linked disorders including Hunter syndrome (mucopolysaccharidosis type II) and Fragile X syndrome (FXS). Single nucleotide mutations in the iduronate 2-sulfatase (IDS) gene at Xq28 most commonly cause Hunter syndrome while a CGG expansion in the FMR1 gene at Xq27.3 is associated with Fragile X syndrome. Gene deletions of the Xq27-28 region are less frequently found in either condition with rare reports in females. Additionally, an association between Xq27-28 deletions and skewed X-inactivation of the normal X chromosome observed in previous studies suggested a primary role of the Xq27-28 region in X-inactivation. Case presentation: We describe the clinical, molecular and biochemical evaluations of a four year-old female patient with global developmental delay and a hemizygous deletion of Xq27.3q28 (144,270,614-154,845,961 bp), a 10.6 Mb region that contains >100 genes including IDS and FMR1. A literature review revealed rare cases with similar deletions that included IDS and FMR1 in females with developmental delay, variable features of Hunter syndrome, and skewed X-inactivation of the normal X chromosome. In contrast, our patient exhibited skewed X-inactivation of the deleted X chromosome and tested negative for Hunter syndrome. Conclusions: This is a report of a female with a 10.6 Mb Xq27-28 deletion with skewed inactivation of the deleted X chromosome. Contrary to previous reports, our observations do not support a primary role of the Xq27-28 region in X-inactivation. A review of the genes in the deletion region revealed several potential genes that may contribute to the patient's developmental delays, and sequencing of the active X chromosome may provide insight into the etiology of this clinical presentation. [ABSTRACT FROM AUTHOR]

Background: X-linked agammaglobulinemia (XLA, OMIM#300,300), caused by mutations in the Bruton tyrosine kinase (BTK) gene, is a rare monogenic inheritable immunodeficiency disorder. Ecthyma gangrenosum is a cutaneous lesion caused by Pseudomonas aeruginosa that typically occurs in patients with XLA and other immunodeficiencies.Case Presentation: We report the case of a 20-month-old boy who presented with fever, vomiting, diarrhea, and ecthyma gangrenosum. Blood, stool, and skin lesion culture samples were positive for P. aeruginosa. A diagnosis of XLA was established, and the c.262G > T mutation in exon 4 of BTK was identified with Sanger sequencing. Symptoms improved following treatment with antibiotics and immunoglobulin infusion.Conclusions: Primary immunodeficiency (i.e., XLA) should be suspected in male infants with P. aeruginosa sepsis, highlighting the importance of genetic and immune testing in these patients. [ABSTRACT FROM AUTHOR]

Background: Barth syndrome (BTHS, OMIM 302060) is a rare, life-threatening, x-linked genetic disorder that occurs almost exclusively in males and is characterized by cardiomyopathy, neutropenia, skeletal muscle myopathy primarily affecting larger muscles, and shorter stature in youth. A greater number of individuals with BTHS are now surviving into adulthood due to advancements in diagnosis and disease management. Given these improvements in life expectancy, understanding the disease experience over time has become increasingly important to individuals with the condition, treatment developers, and regulatory agencies. A study was conducted to explore the experience of BTHS from the perspective of adult males at least 35 years of age with the condition via in-depth qualitative interviews.Results: Findings showed that adults with BTHS experienced a variety of signs/symptoms with variable onset and severity throughout their lives, the most frequently reported being the symptoms of tiredness, muscle weakness, and a fast and/or irregular heart rate, and the sign of short stature in youth. These signs/symptoms negatively impacted individuals' emotional, physical, social, and role functioning. Tiredness and weakness impacted some individuals' physical functioning from an early age and into adulthood. These symptoms generally worsened over time, increasingly interfering with individuals' ability to fully participate in paid and unpaid labor and to partake in family and leisure activities.Conclusions: This research complements recent studies characterizing the potentially degenerative and progressive nature of BTHS and can encourage future research into the natural history and progression of BTHS in untreated individuals. Participants' interview responses revealed a range of symptoms and the potential for multiple impacts on individuals' physical, social, emotional, and role functioning as a result of BTHS symptoms, yet also revealed variability in severity of experience as well as the possibility of resilience and adaptation to the condition. [ABSTRACT FROM AUTHOR]

Background: X-linked hypophosphatemic rickets (XLH) is the first cause of inherited hypophosphatemia and is caused by mutation in the PHEX gene, resulting in excessive expression of the phosphaturic factor FGF23. Symptoms are mainly related to rickets in children and osteomalacia in adults and cause several complications that can be highly invalidating. Due to its rarity, XLH is poorly known and diagnosis is frequently delayed. Conventional treatment is based on oral phosphate salts supplementation and activated vitamin D analogs, which however, cannot cure the disease in most cases. Objective: Due to the low prevalence of XLH, an experts' opinion survey was conducted across Italian centers to collect data on XLH and on its management. Methods: A questionnaire was developed by a group of experts to collect data on XLH epidemiology, diagnosis and treatment in Italy. Results: Data from 10 Italian centers (nine of which pediatric) on 175 patients, followed between 1998 and 2017, were included in the survey. Most patients were followed since childhood and 63 children became adults during the investigated period. The diagnosis was made before the age of 1 and between 1 and 5 years in 11 and 50% of cases, respectively. Clinically apparent bone deformities were present in 95% of patients. These were ranked moderate/severe in 75% of subjects and caused growth stunting in 67% of patients. Other frequent complications included bone pain (40%), dental abscesses (33%), and dental malpositions (53%). Treatment protocols varied substantially among centers. Nephrocalcinosis was observed in 34% of patients. Tertiary hyperparathyroidism developed in 6% of patients. Conclusions: XLH remains a severe condition with significant morbidities. [ABSTRACT FROM AUTHOR]

Background: Mutation of the IL2RG gene results in a form of severe combined immune deficiency (SCID-X1), which has been treated successfully with hematopoietic stem cell gene therapy. SCID-X1 gene therapy results in reconstitution of the previously lacking T cell compartment, allowing analysis of the roles of T cell immunity in humans by comparing before and after gene correction. Methods: Here we interrogate T cell reconstitution using four forms of high throughput analysis. (1) Estimation of the numbers of transduced progenitor cells by monitoring unique positions of integration of the therapeutic gene transfer vector. (2) Estimation of T cell population structure by sequencing of the recombined T cell receptor (TCR) beta locus. (3) Metagenomic analysis of microbial populations in oropharyngeal, nasopharyngeal, and gut samples. (4) Metagenomic analysis of viral populations in gut samples. Results: Comparison of progenitor and mature T cell populations allowed estimation of a minimum number of cell divisions needed to generate the observed populations. Analysis of microbial populations showed the effects of immune reconstitution, including normalization of gut microbiota and clearance of viral infections. Metagenomic analysis revealed enrichment of genes for antibiotic resistance in gene-corrected subjects relative to healthy controls, likely a result of higher healthcare exposure. Conclusions: This multi-omic approach enables the characterization of multiple effects of SCID-X1 gene therapy, including T cell repertoire reconstitution, estimation of numbers of cell divisions between progenitors and daughter T cells, normalization of the microbiome, clearance of microbial pathogens, and modulations in antibiotic resistance gene levels. Together, these results quantify several aspects of the long-term efficacy of gene therapy for SCID-X1. This study includes data from ClinicalTrials.gov numbers NCT01410019, NCT01175239, and NCT01129544. [ABSTRACT FROM AUTHOR]

Background: Mutations in the X-linked gene filamin A (FLNA), encoding the actin-binding protein FLNA, cause a wide spectrum of connective tissue, skeletal, cardiovascular and/or gastrointestinal manifestations. Males are typically more severely affected than females with common pre- or perinatal death. Case presentation: We provide a genotype- and phenotype-oriented literature overview of FLNA hemizygous mutations and report on two live-born male FLNA mutation carriers. Firstly, we identified a de novo, missense mutation (c.238C > G, p.(Leu80Val)) in a five-year old Indian boy who presented with periventricular nodular heterotopia, increased skin laxity, joint hypermobility, mitral valve prolapse with regurgitation and marked facial features (e.g. a flat face, orbital fullness, upslanting palpebral fissures and low-set ears). Secondly, we identified two cis-located FLNA mutations (c.7921C > G, p.(Pro2641Ala); c.7923delC, p.(Tyr2642Thrfs*63)) in a Bosnian patient with Ehlers-Danlos syndrome-like features such as skin translucency and joint hypermobility. This patient also presented with brain anomalies, pectus excavatum, mitral valve prolapse, pulmonary hypertension and dilatation of the pulmonary arteries. He died from heart failure in his second year of life. Conclusions: These two new cases expand the list of live-born FLNA mutation-positive males with connective tissue disease from eight to ten, contributing to a better knowledge of the genetic and phenotypic spectrum of FLNA-related disease. [ABSTRACT FROM AUTHOR]

Background: The link between the protocadherin-19 (PCDH19) gene and epilepsy suggests that an unusual form of X-linked inheritance affects females but is transmitted through asymptomatic males. Individuals with epilepsy associated with mutations in the PCDH19 gene display generalized or focal seizures with or without fever sensitivity. The clinical manifestation of the condition ranges from mild to severe, resulting in intellectual disability and behavioural disturbance. In the present study, we assessed mutations in the PCDH19 gene and the clinical features of a group of Chinese patients with early infantile epileptic encephalopathy and aimed to provide further insight into the understanding of epilepsy and mental retardation limited to females (EFMR; MIM 300088). Case Presentation: We described three variations in the PCDH19 gene in Chinese patients with epilepsy who developed generalized seizures occurring in clusters with or without triggering by fever. Candidate genes were screened for mutations that cause epilepsy and related paroxysmal or nervous system diseases in the coding exons and intron–exon boundaries using polymerase chain reaction (PCR) of genomic deoxyribonucleic acid (DNA) followed by sequencing. The variations were sequenced using next-generation sequencing technology and verified with first-generation sequencing. Exome sequencing of a multigene epilepsy panel revealed three mutations in the PCDH19 gene in a mosaic male and two unrelated females. These included a frameshift mutation c.1508_1509insT (p.Thr504HisfsTer19), a missense mutation c.1681C > T (p.Pro561Ser) and a nonsense mutation c.918C > G (p.Tyr306Ter). Of the three mutations in the PCDH19 gene associated with early infantile epileptic encephalopathy, the frameshift variation in a mosaic male is novel and de novo, the missense variation is de novo and is the second ever reported in females, and the nonsense variation was inherited from the paternal line and is the first example discovered in a female. Conclusions: The results from our current study provide new insight into and perspectives for the molecular genetic link between epilepsy and PCDH19 alterations. Moreover, our new findings of the male mosaic variant broaden the spectrum of PCDH19-related epilepsy and provide a new understanding of this complex genetic disorder. [ABSTRACT FROM AUTHOR]

Background: Testis-expressed gene 11 (TEX11) is an X-linked gene and essential for meiotic recombination and chromosomal synapsis. TEX11 deficiency causes meiotic arrest and male infertility, and many TEX11 mutations have been found in azoospermic and infertile men. Case presentation: This study reported one novel TEX11 mutation (2653G → T, in exon 29, GenBank accession number, NM_031276) in two brothers with azoospermia. This mutation was firstly screened out by whole-exome sequencing (WES) and further verified by amplifying and sequencing the specific exon 29. Surprisingly, the same exonic missense mutation (W856C) was observed in two brothers but not in their mother. Histological analysis of testicular biopsy from both brothers revealed meiotic arrest and no post-meiotic round spermatids and mature spermatozoa were observed in the seminiferous tubules. TEX11 expression was observed strongly in spermatogonia and weakly in spermatocytes, but not in Sertoli cells and interstitial cells. Conclusions: We identified one novel TEX11 mutation in two brothers and summarized the literature regarding TEX11 mutations and male infertility. This study and previous literature indicate that TEX11 mutations are closely associated with male infertility, especially azoospermia, although auxiliary clinical analyses are needed to figure out the causes of male infertility. [ABSTRACT FROM AUTHOR]

Background: Fetal sex determination is useful for families at risk of X-linked disorders, such as Duchenne muscular dystrophy, adrenal hypoplasia, hemophilia. At first, this could be obtained through invasive procedures such as amniocentesis and chorionic villus sampling, having a 1% risk of miscarriage. Since the discovery of cell-free fetal DNA (cffDNA) in maternal plasma, noninvasive prenatal testing permits the early diagnosis of fetal sex through analysis of cffDNA. However, the low amount of cffDNA relative to circulating maternal DNA requires highly sensitive molecular techniques in order to perform noninvasive prenatal diagnosis. In this context we employed droplet digital PCR (ddPCR) in order to evaluate the earliest possible fetal sex determination from circulating DNA extracted from plasma of pregnant women at different gestational ages. Methods: We identified the fetal sex on cffDNA extracted from 29 maternal plasma samples at early gestational ages, several of them not suitable for qPCR determination, using ddPCR designed for SRY gene target. Results: All maternal plasma samples were determined correctly for SRY gene target using ddPCR even at very early gestational age (prior to 7 weeks). Conclusions: The ddPCR is a robust, efficient and reliable technology for the earliest possible fetal sex determination from maternal plasma. [ABSTRACT FROM AUTHOR]