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This paper reports the first published prevalence of Multiple endocrine neoplasia type 2B (MEN 2B). Estimates of the epidemiology of MEN 2B were based on a single population with one centralized genetic clinic. MEN 2B remains a relatively rare condition and can be easily missed if the diagnosis has not been considered. [ABSTRACT FROM AUTHOR]

Mitochondrial respiratory chain diseases represent one of the most common inherited neurometabolic disorders of childhood, affecting a minimum of 1 in 7500 live births. The marked clinical, biochemical, and genetic heterogeneity means that accurate genetic counselling relies heavily upon the identification of the underlying causative mutation in the individual and determination of carrier status in the parents. Isolated complex I deficiency is the most common respiratory chain defect observed in children, resulting in organ-specific or multisystem disease, but most often presenting as Leigh syndrome, for which mitochondrial DNA mutations are important causes. Several recurrent, pathogenic point mutations in the MTND3 gene - including m.10191T>C ( p.Ser45Pro) - have been previously identified. In this short clinical review we evaluate the case reports of the m.10191T>C mutation causing complex I-deficient Leigh syndrome described in the literature, in addition to two new ones diagnosed in our laboratory. Both of these appear to have arisen de novo without transmission of the mutation from mother to offspring, illustrating the importance not only of fully characterizing the mitochondrial genome as part of the investigation of children with complex I-deficient Leigh syndrome but also of assessing maternal samples to provide crucial genetic advice for families. [ABSTRACT FROM AUTHOR]

MLL2 mutations are detected in 55 to 80% of patients with Kabuki syndrome (KS). In 20 to 45% patients with KS, the genetic basis remains unknown, suggesting possible genetic heterogeneity. Here, we present the largest yet reported cohort of 116 patients with KS. We identified MLL2 variants in 74 patients, of which 47 are novel and a majority are truncating. We show that pathogenic missense mutations were commonly located in exon 48. We undertook a systematic facial KS morphology study of patients with KS at our regional dysmorphology meeting. Our data suggest that nearly all patients with typical KS facial features have pathogenic MLL2 mutations, although KS can be phenotypically variable. Furthermore, we show that MLL2 mutation-positive KS patients are more likely to have feeding problems, kidney anomalies, early breast bud development, joint dislocations and palatal malformations in comparison with MLL2 mutation-negative patients. Our work expands the mutation spectrum of MLL2 that may help in better understanding of this molecule, which is important in gene expression, epigenetic control of active chromatin states, embryonic development and cancer. Our analyses of the phenotype indicates that MLL2 mutation-positive and -negative patients differ systematically, and genetic heterogeneity of KS is not as extensive as previously suggested. Moreover, phenotypic variability of KS suggests that MLL2 testing should be considered even in atypical patients. [ABSTRACT FROM AUTHOR]

Pediatric endocrine tumors are rare but have fairly characteristic presentations. We describe an approach to diagnosis and management of five of the most common presentations including gonadoblastoma, paraganglioma,medullary thyroid cancer, adrenal cancer, and pituitary adenoma. Genetic testing can aid in the early detection and prevention and management of tumors in patients and in other family members. [ABSTRACT FROM AUTHOR]

The article offers information on tuberous sclerosis complex (TSC), a rare disorder causing brain tumors, citing a case study of an 8-year-old boy with TSC2 1801A>G mutation. A clinical image of the patient showing forehead plaque, angiofibromas and shagreen patch is presented, which forms major features for diagnosis of TSC. The need for oncologists to correctly diagnose TSC in patients with renal tumors is highlighted. Treatment of subependymal giant cell astrocytomas (SEGAs) is included.