Role of cross-campus multidisciplinary team meetings in decision-making for children and adolescents with differences of sex development/intersex.

AIM: Management of children with differences/disorders of sex development (DSD) is complex with limited evidence to guide clinical decisions. Regular multidisciplinary team meetings were set up in Sydney and Melbourne paediatric hospitals to enable systematic peer review of complex decision-making. We aim to describe the workload and role of these meetings. METHODS: The multidisciplinary team forum includes invited representatives from endocrinology, urology, gynaecology, genetics, psychology, social work, clinical ethics, laboratory and hospital executive and meetings occur 1-3 times monthly. Descriptive data were collected from de-identified meeting referrals and minutes between August 2012 to August 2018 (Sydney) and January 2014 to August 2018 (Melbourne). RESULTS: A total of 192 referrals (142 new and 50 follow-ups) aged 1 week to 17 years were discussed across the two sites. 46, XY DSD (n = 81) was the most common sub-classification. Consideration of surgical options and optimal management of gonads with malignant potential were amongst the common reasons for referral to the multidisciplinary team meetings. Surgical interventions were considered but not recommended after review for 38 of 154 (24.7%) procedures. Gonad retention to allow potential functional benefit was recommended in 15/46 (32.6%) referrals. Evidence of premalignant or malignant changes was found in 20/57 (35%) gonads removed, with dysgenetic features and atrophy/streak features in 6 (10.5%) and 27 (47.4%) gonads respectively. CONCLUSION: Formal DSD multidisciplinary team meetings provide a framework and opportunity for multi and interdisciplinary discussions amongst representatives from several specialities to help make complex decision-making.

TP63-truncating variants cause isolated premature ovarian insufficiency.

Premature ovarian insufficiency involves amenorrhea and elevated follicle-stimulating hormone before age 40, and its genetic basis is poorly understood. Here, we study 13 premature ovarian insufficiency (POI) patients using whole-exome sequencing. We identify PREPL and TP63 causative variants, and variants in other potentially novel POI genes. PREPL deficiency is a known cause of syndromic POI, matching the patients' phenotype. A role for TP63 in ovarian biology has previously been proposed but variants have been described in multiorgan syndromes, and not isolated POI. One patient with isolated POI harbored a de novo nonsense TP63 variant in the terminal exon and an unrelated patient had a different nonsense variant in the same exon. These variants interfere with the repression domain while leaving the activation domain intact. We expand the phenotypic spectrum of TP63-related disorders, provide a new genotype:phenotype correlation for TP63 and identify a new genetic cause of isolated POI.

Identification of variants in pleiotropic genes causing "isolated" premature ovarian insufficiency: implications for medical practice.

Next-generation sequencing (NGS) is increasingly being used in a clinical setting for the molecular diagnosis of patients with heterogeneous disorders, such as premature ovarian insufficiency (POI). We performed NGS of ~1000 candidate genes in four unrelated patients with POI. We discovered the genetic cause of "isolated" POI in two cases, both of which had causative variants in surprising genes. In the first case, a homozygous nonsense variant in NBN was causative. Recessive function-altering NBN variants typically cause Nijmegen breakage syndrome characterized by microcephaly, cancer predisposition, and immunodeficiency, none of which are evident in the patient. At a cellular level, we found evidence of chromosomal instability. In the second case, compound heterozygous variants in EIF2B2 were causative. Recessive EIF2B2 function-altering variants usually cause leukoencephalopathy with episodic decline. Subsequent MRI revealed subclinical neurological abnormalities. These cases demonstrate that variants in NBN and EIF2B2, which usually cause severe syndromes, can cause apparently isolated POI, and that (1) NGS can precede clinical diagnosis and guide patient management, (2) NGS can redefine the phenotypic spectrum of syndromes, and (3) NGS may make unanticipated diagnoses that must be sensitively communicated to patients. Although there is rigorous debate about the handling of secondary/incidental findings using NGS, there is little discussion of the management of causative pleiotropic gene variants that have broader implications than that for which genetic studies were sought.

Functional characterization of novel NR5A1 variants reveals multiple complex roles in disorders of sex development.

Variants in the NR5A1 gene encoding SF1 have been described in a diverse spectrum of disorders of sex development (DSD). Recently, we reported the use of a targeted gene panel for DSD where we identified 15 individuals with a variant in NR5A1, nine of which are novel. Here, we examine the functional effect of these changes in relation to the patient phenotype. All novel variants tested had reduced trans-activational activity, while several had altered protein level, localization, or conformation. In addition, we found evidence of new roles for SF1 protein domains including a region within the ligand binding domain that appears to contribute to SF1 regulation of Müllerian development. There was little correlation between the severity of the phenotype and the nature of the NR5A1 variant. We report two familial cases of NR5A1 deficiency with evidence of variable expressivity; we also report on individuals with oligogenic inheritance. Finally, we found that the nature of the NR5A1 variant does not inform patient outcomes (including pubertal androgenization and malignancy risk). This study adds nine novel pathogenic NR5A1 variants to the pool of diagnostic variants. It highlights a greater need for understanding the complexity of SF1 function and the additional factors that contribute.