The adaptor protein-2 sigma subunit (AP2σ2) is pivotal for clathrin-mediated endocytosis of plasma membrane constituents such as the calcium-sensing receptor (CaSR). Mutations of the AP2σ2 Arg15 residue result in familial hypocalciuric hypercalcaemia type 3 (FHH3), a disorder of extracellular calcium (Ca2+o) homeostasis. To elucidate the role of AP2σ2 in Ca2+o regulation, we investigated 65 FHH probands, without other FHH-associated mutations, for AP2σ2 mutations, characterized their functional consequences and investigated the genetic mechanisms leading to FHH3. AP2σ2 mutations were identified in 17 probands, comprising 5 Arg15Cys, 4 Arg15His and 8 Arg15Leu mutations. A genotype–phenotype correlation was observed with the Arg15Leu mutation leading to marked hypercalcaemia. FHH3 probands harboured additional phenotypes such as cognitive dysfunction. All three FHH3-causing AP2σ2 mutations impaired CaSR signal transduction in a dominant-negative manner. Mutational bias was observed at the AP2σ2 Arg15 residue as other predicted missense substitutions (Arg15Gly, Arg15Pro and Arg15Ser), which also caused CaSR loss-of-function, were not detected in FHH probands, and these mutations were found to reduce the numbers of CaSR-expressing cells. FHH3 probands had significantly greater serum calcium (sCa) and magnesium (sMg) concentrations with reduced urinary calcium to creatinine clearance ratios (CCCR) in comparison with FHH1 probands with CaSR mutations, and a calculated index of sCa × sMg/100 × CCCR, which was ≥ 5.0, had a diagnostic sensitivity and specificity of 83 and 86%, respectively, for FHH3. Thus, our studies demonstrate AP2σ2 mutations to result in a more severe FHH phenotype with genotype–phenotype correlations, and a dominant-negative mechanism of action with mutational bias at the Arg15 residue.

These are the first UK case reports of Type 2 diabetes in children. Paediatricians need to be aware of the risk of Type 2 diabetes developing in childhood in high-risk ethnic groups, particularly in association with obesity and a positive family history.

Ethnic differences in insulin sensitivity are associated with ethnic differences in body fat. South Asian adolescents are more insulin resistant, with more body fat than white European adolescents, which may contribute to their increased risk of developing type 2 diabetes.

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Study Type – Therapy (case series)Level of Evidence 4What's known on the subject? and What does the study add?Approximately 200 cases of persistent Müllerian duct syndrome have been reported over the last 50 years and most authors suggest leaving the Müllerian remnant in situ because of the difficulty in dissection and the presumed absence of risk of malignancy. However, with increasing reports of Müllerian malignancies emerging, we report our 10‐year experience of managing patients with persistent Müllerian duct syndrome, with removal of müllerian remnants.This case series shows that there is an increased risk of Müllerian malignancy that was previously unknown. With the laparoscopic approach, orchidopexy with simultaneous removal of Müllerian remnants could be accomplished with minimal surgical trauma and the benefit of no malignancy risk in the future. This is a new technique that has not been previously performed. Considering the current evidence of malignancy in the Müllerian remnant, surgeons would need to discuss with families about removal of remnants or long‐term monitoring.OBJECTIVES To describe the presentation and management of eight patients with persistent Müllerian duct syndrome (PMDS) seen over a 10‐year period at our tertiary centre. To review the literature of Müllerian malignancies reported in PMDS. PATIENTS AND METHODS The hospital records of eight patients with PMDS were retrospectively reviewed between 2001 and 2011. Extensive PubMed searches for PMDS and Müllerian malignancy were performed. RESULTS Eleven cases with PMDS and malignancy of the Müllerian remnants were identified. From our own PMDS series: five males presented with bilateral undescended testes and three had unilateral undescended testis. We found that the Müllerian remnants could be removed by laparoscopy and three patients had simultaneous laparoscopic removal of the Müllerian structures and laparoscopic orchidopexy. CONCLUSIONS The principle aim of orchidopexy with simultaneous laparoscopic removal of the Müllerian structures can be accomplished with minimal surgical trauma and the benefit of no malignancy risk in the future. Surgeons should consider excision of the Müllerian remnants where possible.

Objective: In children with congenital hyperinsulinism (CHI), K ATP channel genes (ABCC8 and KCNJ11) can be screened rapidly for potential pathogenic mutations. We aimed to assess the contribution of rapid genetic testing to the clinical management of CHI. Design: Follow-up observational study at two CHI referral hospitals. Methods: Clinical outcomes such as subtotal pancreatectomy, 18 F-Dopa positron emission tomography-computed tomography (PET-CT) scanning, stability on medical treatment and remission were assessed in a cohort of 101 children with CHI. Results: In total, 32 (32%) children had pathogenic mutations in K ATP channel genes (27 in ABCC8 and five in KCNJ11), of which 11 (34%) were novel. In those negative at initial screening, other mutations (GLUD1, GCK, and HNF4A) were identified in three children. Those with homozygous/compound heterozygous ABCC8/KCNJ11 mutations were more likely to require a subtotal pancreatectomy CHI (7/10, 70%). Those with paternal heterozygous mutations were investigated with 18 F-Dopa PET-CT scanning and 7/13 (54%) had a focal lesionectomy, whereas four (31%) required subtotal pancreatectomy for diffuse CHI. Those with maternal heterozygous mutations were most likely to achieve remission (5/5, 100%). In 66 with no identified mutation, 43 (65%) achieved remission, 22 (33%) were stable on medical treatment and only one child required a subtotal pancreatectomy. Conclusions: Rapid genetic analysis is important in the management pathway of CHI; it provides aetiological confirmation of the diagnosis, indicates the likely need for a subtotal pancreatectomy and identifies those who require 18 F-Dopa PET-CT scanning. In the absence of a mutation, reassurance of a favourable outcome can be given early in the course of CHI.

Introduction: Neuroglycopenia is recognized to be associated with abnormal neurodevelopmental outcomes in 26–44% of children with persistent congenital hyperinsulinism (P-CHI). The prevalence of abnormal neurodevelopment in transient CHI (T-CHI) is not known. We have aimed to investigate abnormal neurodevelopment and associated factors in T-CHI and P-CHI.Materials and Methods: A cohort of children with CHI (n = 67, age 2.5–5 years) was assessed at follow-up review and noted to have normal or abnormal (mild or severe) neurodevelopmental outcomes for the domains of speech and language, motor, and vision. Children were classified as P-CHI (n = 33), if they had undergone surgery or remained on medical therapy, or T-CHI (n = 34), if medical treatment for hypoglycemia was stopped.Results: Overall, abnormal neurodevelopment was present in 26 (39%) children with CHI, of whom 18 (69%) were severe. Importantly, the incidence of abnormal neurodevelopment in T-CHI was similar to that in P-CHI (30 vs. 47% respectively, p = 0.16). The prevalence of severe abnormal neurodevelopment in speech, motor, and vision domains was similar in both T-CHI and P-CHI children. For this cohort, we found that the severity of disease [based upon maximal diazoxide dose (odds ratio 95% confidence intervals) 1.3 (1.1; 1.5), p = 0.03], and early presentation of CHI <7 days following birth [5.9 (1.3; 27.8), p = 0.02] were significantly associated with abnormal neurodevelopment. There was no significant association with gender, genotype, or the histopathological basis of CHI.Conclusion: Abnormal neurodevelopment was evident in one third of children with both T-CHI and P-CHI, early presentation and severe CHI being risk factors. Early recognition and rapid correction of hypoglycemia are advocated to avoid abnormal neurodevelopment in children with CHI.

Murine gammaherpesvirus is a natural pathogen ofwild mice. The virus infects alveolar cells and spleen cells during the primary infection and establishes a latent/persistent infection in B lymphocytes. Little is known