Thioredoxin Reductase 2 (TXNRD2) Variant As A Cause Of Micropenis, Undescended Testis And Selective Glucocorticoid Deficiency.

INTRODUCTION: Variants in genes that play a role in maintaining cellular redox homeostasis in adrenocortical cells may be associated with glucocorticoid deficiency and it is unclear whether these cases may be associated with a wider phenotype. However, to date, only one case of a genetic variant in TXNRD2, the gene encoding thioredoxin reductase Type 2, in a South Asian kindred with familial glucocorticoid deficiency has been reported. CASE PRESENTATION: The index case was diagnosed with selective glucocorticoid deficiency at 10 years of age. He had a history of a small penis and a right undescended testis which subsequently required an orchidopexy. The parents were of Pakistani origin and first cousins. The boy's gonadal function was normal and autosomal recessive missense homozygous variants p.Val361Met;Val361Met in thioredoxin reductase 2 gene (TXNRD2) were identified in him by WGS. Functional studies were performed using peripheral blood mononuclear cells (PBMCs) from the patient, unaffected parents and four age-matched healthy boys. Compared to the carriers and controls, the case had lower TXNRD2 protein on immunoblotting using anti-TXNRD2 antibody (1.3 fold) 95% CI: 1.8 (1.5-2.1), lower mRNA expression of TXNRD2 on quantitative RT-PCR (1.6 fold) 95% CI: 1.1 (0.7-1.4) and a lower glutathione (GSH):oxidized glutathione (GSSG) ratio (6.7 fold) 95% CI: 2.0 (1.6-2.4). CONCLUSIONS: In addition to confirming the critical role that TXNRD2 serves in maintaining adrenal function, by reporting the findings of atypical genitalia, this case further extends the phenotype.

The I-CAH Registry: A platform for international collaboration for improving knowledge and clinical care in congenital adrenal hyperplasia.

To provide an overview of the I-CAH Registry. Following the successful roll-out of the I-DSD Registry in the 2000s, it was felt that there was a need for a registry for congenital adrenal hyperplasia (CAH) and this was launched in 2014 as a dedicated module within the original registry. In addition to supporting and promoting research, the I-CAH Registry acts as an international tool for benchmarking of clinical care and it does this through the collection of standardised data for specific projects. Surveillance of novel therapies in the field of CAH can also be achieved via global collaborations. Its robust governance ensures adherence to the international standards for rare disease registries. Rare disease registries such as the I-CAH Registry are important tools for all stakeholders involved in the care of people with CAH.

I-DSD: The First 10 Years.

BACKGROUND: Research and audit are vital for the management of Differences/Disorders of Sex Development (DSD). Clinical networks have a strong potential to drive these activities with the development of care standards including patient experience data and peer-observation of clinical care provision. SUMMARY: Following the 2005 Consensus Workshop that stressed the need for the regular collection and sharing of data across geographical boundaries, the current I-DSD registry was initially launched in 2008. Over a decade later, this registry and its associated network play an increasingly important role in supporting research, training, and benchmarking of care and service. Patient registries can also facilitate the development of local circles of patients and parents with similar conditions who can support each other. KEY MESSAGES: The case for participating in standardized data collection and exchange for DSD has now been made and should be standard practice in centres that care for people with DSD.

A Nationwide Study of the Prevalence and Initial Management of Atypical Genitalia in the Newborn in Scotland.

Provision of optimum healthcare for infants with atypical genitalia requires a clear understanding of the occurrence of this condition. The objective of this study was to determine the prevalence of atypical genitalia and its initial management. A prospective, electronic survey of clinicians within managed clinical networks in Scotland was undertaken between 2013 and 2019. Notification from clinicians was sought for term neonates requiring specialist input for atypical genitalia. Additional information was also sought from the 4 regional genetics laboratories that provided details for neonates who had an urgent karyotype performed for atypical genitalia or sex determination. In total, the study identified 171 term infants who required some investigation for atypical genitalia in the neonatal period, providing a birth prevalence of 1:1,881 term births. Of the 171 infants, 97 (57%) had specialist input over the first 3 months of life, providing a birth prevalence of 1:3,318 term births that received specialist input for atypical genitalia. A total of 92 of these 97 cases had complete 3-month follow-up data, 62 (67%) presented within 24 h of birth, and age at presentation ranged from birth to 28 days. Age at sex assignment ranged from birth to 14 days, and in 63 cases (68%), sex assignment occurred at birth. Thus, the birth prevalence of a case of atypical genitalia where sex assignment was reported to be delayed beyond birth was estimated at 1:11,097 births. In 1 case sex was re-assigned at 3 months. Atypical genitalia requiring specialist input within the first month of life are rare in term newborns, and in only a third of these cases, sex assignment is delayed beyond birth. This study provides new clinical benchmarks for comparing and improving the delivery of care in centres that manage these conditions.

Muscle deficits with normal bone microarchitecture and geometry in young adults with well-controlled childhood-onset Crohn's disease.

BACKGROUND: Muscle-bone deficits are common in pediatric Crohn's disease; however, few studies have assessed long-term musculoskeletal outcomes in adults with childhood-onset Crohn's disease. This study assessed the prevalence of musculoskeletal deficits in young adults with childhood-onset Crohn's disease compared with healthy controls. METHODS: High-resolution MRI and MR spectroscopy were used to assess bone microarchitecture, cortical geometry and muscle area, and adiposity at distal femur and bone marrow adiposity (BMA) at lumbar spine. Muscle function and biomarkers of the muscle-bone unit were also assessed. RESULTS: Twenty-seven adults with Crohn's disease with median (range) age 23.2 years (18.0, 36.1) and 27 age and sex-matched controls were recruited. Trabecular microarchitecture, cortical geometry and BMA were not different between Crohn's disease and controls (P > 0.05 for all). Muscle area was lower (P = 0.01) and muscle fat fraction was higher (P = 0.04) at the distal femur in Crohn's disease compared to controls. Crohn's disease participants had lower grip strength [-4.3 kg (95% confidence interval (CI), -6.8 to -1.8), P = 0.001] and relative muscle power [-5.0 W/kg (95% CI, -8.8 to -1.2), P = 0.01]. Crohn's disease activity scores negatively associated with trabecular bone volume (r = -0.40, P = 0.04) and muscle area (r = -0.41, P = 0.03). CONCLUSION: Young adults with well-controlled Crohn's disease managed with contemporary therapies did not display abnormal bone microarchitecture or geometry at the distal femur but exhibited muscle deficits. The observed muscle deficits may predispose to musculoskeletal morbidity in future and interventions to improve muscle mass and function warrant investigation.

Skeletal Fragility and Its Clinical Determinants in Children With Type 1 Diabetes.

CONTEXT: Type 1 diabetes (T1D) is associated with an increased fracture risk at all ages. OBJECTIVE: To understand the determinants of bone health and fractures in children with T1D. DESIGN: Case-control study of children with T1D on bone-turnover markers, dual-energy X-ray absorptiometry, and 3 Tesla-MRI of the proximal tibia to assess bone microarchitecture and vertebral marrow adiposity compared with age- and sex-matched healthy children. RESULTS: Thirty-two children with T1D at a median (range) age of 13.7 years (10.4, 16.7) and 26 controls, aged 13.8 years (10.2, 17.8), were recruited. In children with T1D, serum bone-specific alkaline phosphatase (BAP) SD score (SDS), C-terminal telopeptide of type I collagen SDS, and total body (TB) and lumbar spine bone mineral density (BMD) SDS were lower (all P < 0.05). Children with T1D also had lower trabecular volume [0.55 (0.47, 0.63) vs 0.59 (0.47, 0.63); P = 0.024], lower trabecular number [1.67 (1.56, 1.93) vs 1.82 (1.56, 1.99); P = 0.004], and higher trabecular separation [0.27 (0.21, 0.32) vs 0.24 (0.20, 0.33); P = 0.001] than controls. Marrow adiposity was similar in both groups (P = 0.25). Bone formation, as assessed by BAP, was lower in children with poorer glycemic control (P = 0.009) and who were acidotic at initial presentation (P = 0.017) but higher in children on continuous subcutaneous insulin infusion (P = 0.025). Fractures were more likely to be encountered in children with T1D compared with controls (31% vs 19%; P< 0.001). Compared with those without fractures, the T1D children with a fracture history had poorer glycemic control (P = 0.007) and lower TB BMD (P < 0.001) but no differences in bone microarchitecture. CONCLUSION: Children with T1D display a low bone-turnover state with reduced bone mineralization and poorer bone microarchitecture.

Persistence of Muscle-bone Deficits Following Anti-tumour Necrosis Factor Therapy in Adolescents With Crohn Disease.

OBJECTIVES: The aim of the study is to assess change in the muscle-bone unit in adolescents with Crohn disease (CD) on anti-tumour necrosis factor (anti-TNFα). METHODS: Prospective study following anti-TNFα in 19 adolescents with CD with a median age (range) of 15.1 years (11.2, 17.2). At baseline, 6 and 12 months, subjects had a biochemical assessment of insulin growth factor axis, bone turnover and muscle-bone health by dual energy absorptiometry (DXA), peripheral quantitative computed tomography (pQCT), and dynamic isometry. RESULTS: Significant clinical improvement in disease activity was observed by 2 weeks (P = 0.004 vs baseline) and maintained at 12 months (P = 0.038 vs baseline). Median bone specific alkaline phosphatase standard deviation score (SDS) increased from -1.7 (-3.6 to -1.0) to -1.2 (-3.6 to -0.5) by 6 weeks (P = 0.01). At baseline, DXA total body and lumbar spine bone mineral density (BMD) SDS was -0.9 (-2.3 to 0.5) and -1.1 (-2.9 to 0.4), respectively. At baseline, pQCT trabecular BMD SDS at 4% tibia and muscle cross-sectional area SDS at 66% radius was -1.6 (-3.2 to 1.1) and -2.4 (-4.3 to -0.3), respectively. At baseline, maximal isometric grip force (MIGF) of the non-dominant hand adjusted for height was -1.5 (-4.5 to 0.49). All these deficits in muscle-bone persisted at 6 and 12 months. CONCLUSIONS: Despite improvement in disease and osteoblast activity, bone and muscle deficits, as assessed by DXA, pQCT, and grip strength in adolescents with CD did not improve following twelve months of anti-TNFα.

An Unbalanced Rearrangement of Chromosomes 4:20 is Associated with Childhood Osteoporosis and Reduced Caspase-3 Levels.

The purpose of this study was to investigate the association of a chromosome 4:20 imbalance with osteoporosis in three related children. Bone biochemistry, bone turnover markers, and dual-energy X-ray absorptiometry (DXA) scanning were performed in all three cases and bone biopsy and histomorphometry in one. The chromosome imbalance was delineated by array comparative genomic hybridization (aCGH) and analyzed for candidate genes. A potential candidate gene within the deleted region is caspase-3, previously linked to low bone mineral density (BMD) in heterozygous mice thus caspase-3 activity was measured in cases and controls. Routine bone biochemistry and markers of bone turnover did not reveal any abnormality. DXA showed reduced total and lumbar spine bone mineral content. aCGH showed an 8 megabase (Mb) deletion of terminal chromosome 4q incorporating a region previously linked to low BMD and a 15 Mb duplication of terminal chromosome 20p. Bone biopsy showed a high bone turnover state, trabecularisation of cortical bone and numerous small osteoclasts coupled with normal bone formation. Basal serum caspase-3 activity was lower in cases compared with controls. We conclude that the early-onset osteoporosis with low basal levels of caspase-3 and abnormal osteoclasts is a feature of this chromosomal translocation. Further investigation of the role of the deleted and duplicated genes and especially caspase-3 is required.

Deficits in Trabecular Bone Microarchitecture in Young Women With Type 1 Diabetes Mellitus.

The pathophysiological mechanism of increased fractures in young adults with type 1 diabetes mellitus (T1DM) is unclear. We conducted a case-control study of trabecular bone microarchitecture and vertebral marrow adiposity in young women with T1DM. Thirty women with T1DM with a median age (range) age of 22.0 years (16.9, 36.1) attending one outpatient clinic with a median age at diagnosis of 9.7 years (0.46, 14.8) were compared with 28 age-matched healthy women who acted as controls. Measurements included MRI-based assessment of proximal tibial bone volume/total volume (appBV/TV), trabecular separation (appTb.Sp), vertebral bone marrow adiposity (BMA), and abdominal adipose tissue and biochemical markers of GH/IGF-1 axis (IGF-1, IGFBP3, ALS) and bone turnover. Median appBV/TV in cases and controls was 0.3 (0.22, 0.37) and 0.33 (0.26, 0.4), respectively (p = 0.018) and median appTb.Sp in T1DM was 2.59 (2.24, 3.38) and 2.32 (2.03, 2.97), respectively (p = 0.012). The median appBV/TV was 0.28 (0.22, 0.33) in those cases with retinopathy (n = 15) compared with 0.33 (0.25, 0.37) in those without retinopathy (p = 0.02). Although median visceral adipose tissue in cases was higher than in controls at 5733 mm(3) (2030, 11,144) and 3460 mm(3) (1808, 6832), respectively (p = 0.012), there was no difference in median BMA, which was 31.1% (9.9, 59.9) and 26.3% (8.5, 49.8) in cases and controls, respectively (p = 0.2). Serum IGF-1 and ALS were also lower in cases, and the latter showed an inverse association to appTbSp (r = -0.30, p = 0.04). Detailed MRI studies in young women with childhood-onset T1DM have shown clear deficits in trabecular microarchitecture of the tibia. Underlying pathophysiological mechanisms may include a microvasculopathy.

A prospective longitudinal study of growth and pubertal progress in adolescents with inflammatory bowel disease.

BACKGROUND: Puberty and growth may be affected in inflammatory bowel disease (IBD) but the extent is unclear. METHODS: We performed a prospective study over 12 months in 63 adolescents (Crohn's disease, CD, n = 45; ulcerative colitis/IBD unclassified, UC, n = 18) with a median age of 13.4 years (range 10-16.6). Assessment included anthropometry, biochemical markers of growth and puberty and an assessment of quality of life by IMPACT-III. RESULTS: Compared to the normal population, boys with CD were shorter, with a median height SDS (HtSDS) of -0.13 (-2.52 to 1.58; p < 0.05). In addition, the study cohort had a lower median IGF-1 SDS of -0.29 (-4.53 to 2.96; p = 0.008) and a higher median IGFBP3 SDS of 0.45 (-3.15 to 2.55; p = 0.002). Over the study period, the median Ht velocity (HV) was 5 cm/year (0.2-8.7) and the change in HtSDS was 0.06 (-0.48 to 0.57). The median difference between the chronological and bone age was 0.3 years (-2.5 to 3.0) and pubertal examination was not delayed. In the whole group, the erythrocyte sedimentation rate (ESR) showed an inverse association with HV (r = -0.29; p = 0.025) and IGF-1:IGFBP3 (r = -0.34; p = 0.016). The score in the body image domain, IMPACT-III, was inversely associated with HtSDS (r = -0.31; p = 0.03). CONCLUSION: Despite no evidence of pubertal delay, adolescents with IBD display growth retardation which may be associated with raised ESR, adverse quality of life measures and an abnormality of IGF-1 bioavailability.

Prevalence of Helicobacter pylori vacA, cagA and iceA genotypes in South African patients with upper gastrointestinal diseases.

Clinical response to Helicobacter pylori infection may be determined by specific virulence-associated genotypes which varies geographically. The aim of this study was to investigate the diversity of putative virulence markers of H. pylori; cagA, vacA and iceA in the Eastern Cape Province of South Africa. One hundred H. pylori strains obtained from dyspeptic patients were used. Gastric biopsies were obtained from 254 dyspeptic patients. H. pylori was cultured and strains were studied. Bacterial genotypes cagA, vacA (s and m subtypes) and iceA were analysed by PCR using specific primers. CagA was identified in 90% of the strains investigated. Fifty-eight of the 100 strains had the vacA signal sequence genotype s1 and 26 had subtype s2. Combined vacA s1/s2 was detected in 16 of the strains. VacA middle region analysis showed that 8 (8%) strains were m1 while 50 were m2. Combined vacA m1/m2 was detected in 36 of the strains. s1m2 (20%) and s2m2 (20%) genotypes were the most common allelic combinations of the vacA gene among the strains. Multiple vacA genotypes were detected in this study. Twenty-six percent of the strains identified had both iceA1 and iceA2. All our strains tested positive for the ureC (glmM) gene. This study reveals a high prevalence of vacA, cagA and iceA2.

Orally efficacious thrombin inhibitors with cyanofluorophenylacetamide as the P2 motif.

2-Cyano-6-fluorophenylacetamide was explored as a novel P2 scaffold in the design of thrombin inhibitors. Optimization around this structural motif culminated in 14, which is a potent thrombin inhibitor (K(i)=1.2nM) that exhibits robust efficacy in canine anticoagulation and thrombosis models upon oral administration.

Molecular determinants of substrate specificity in plant 5'-methylthioadenosine nucleosidases.

5'-Methylthioadenosine (MTA)/S-adenosylhomocysteine (SAH) nucleosidase (MTAN) is essential for cellular metabolism and development in many bacterial species. While the enzyme is found in plants, plant MTANs appear to select for MTA preferentially, with little or no affinity for SAH. To understand what determines substrate specificity in this enzyme, MTAN homologues from Arabidopsis thaliana (AtMTAN1 and AtMTAN2, which are referred to as AtMTN1 and AtMTN2 in the plant literature) have been characterized kinetically. While both homologues hydrolyze MTA with comparable kinetic parameters, only AtMTAN2 shows activity towards SAH. AtMTAN2 also has higher catalytic activity towards other substrate analogues with longer 5'-substituents. The structures of apo AtMTAN1 and its complexes with the substrate- and transition-state-analogues, 5'-methylthiotubercidin and formycin A, respectively, have been determined at 2.0-1.8 A resolution. A homology model of AtMTAN2 was generated using the AtMTAN1 structures. Comparison of the AtMTAN1 and AtMTAN2 structures reveals that only three residues in the active site differ between the two enzymes. Our analysis suggests that two of these residues, Leu181/Met168 and Phe148/Leu135 in AtMTAN1/AtMTAN2, likely account for the divergence in specificity of the enzymes. Comparison of the AtMTAN1 and available Escherichia coli MTAN (EcMTAN) structures suggests that a combination of differences in the 5'-alkylthio binding region and reduced conformational flexibility in the AtMTAN1 active site likely contribute to its reduced efficiency in binding substrate analogues with longer 5'-substituents. In addition, in contrast to EcMTAN, the active site of AtMTAN1 remains solvated in its ligand-bound forms. As the apparent pK(a) of an amino acid depends on its local environment, the putative catalytic acid Asp225 in AtMTAN1 may not be protonated at physiological pH and this suggests the transition state of AtMTAN1, like human MTA phosphorylase and Streptococcus pneumoniae MTAN, may be different from that found in EcMTAN.