ESPE Abstracts

Disorders of sex development (DSD) are a group of congenital developmental disorders in which the chromosomal, gonadal, or anatomical sex is atypical. The clinical diagnosis and management of DSD are difficult and complex because of the various aetiology and diverse manifestation. The project ‘Genetics of Human Disorders of Sexual Development’ is funded by Swiss National Science Foundation and fulfilled by the University of Geneva Medical School (Switzerland), the Me...

Background: Rodent models of leptin inactivity show progressive obesity due to exaggerated food intake. In humans, only rare monogenic cases of leptin deficiency and almost absent circulating leptin levels have been identified. Recently, two cases of children with early onset massive obesity due to biofunctionally inactive leptin in the face of normal total levels have been identified.Objective and hypotheses: Here we aimed to identify leptin inactivity ...

Background: Congenital hypogonadotropic hypogonadism (HH) is a rare but clinically and genetically heterogeneous disease characterized by an absent or incomplete puberty and infertility. The association of HH with hyposmia or anosmia is defined as Kallmann syndrome. Molecular genetic testing of HH is valuable, as it can prompt the treatment in adolescence.Objective and hypotheses: To identify causative variants in genes associated with HH in a cohort of ...

Background: Acromesomelic dysplasia Maroteaux type (AMDM) (OMIM 602875) is a rare autosomal recessive skeletal disorder with an approximate prevalence of 1/1,000,000) and characterized by severe dwarfism accompanied by shortness of distal and middle segments of extremities. Mutations in the NPR2 gene which encodes for the natriuretic peptide receptor B (NPR-B) is the underlying genetic cause of this disorder.Objective and hypotheses: Genetic con...

Background: Turner syndrome, a condition that affects only girls and women, result when the X chromosome is missing or partially missing. Ornithine transcarbamylase (OTC) deficiency, the most common inherited urea cycle disorder, is transmitted as a partially dominant X-linked trait. The OTC gene maps to Xp21.1 and spans approximately 73 kb, containing 10 exons and 9 introns. OTC deficiency is diagnosed using a combination of clinical findings and biochemical testing, while co...

Background: Genetic defects in NKX2.1 (chromosome 14q13) are associated with hypothyroidism, choreo-athetotic movements and respiratory distress, known as the “Brain-Lung-Thyroid syndrome”.Objective and hypotheses: To identify the genetic basis of a disorder compatible with the “NKX2.1 syndrome” and extra features outside the typical triad.Patients and methods: 10-year old girl with congenital ...

Background: Type 2 diabetes in children and adolescents is a rare disease with an estimated incidence (age 0–20 years) of below 5/100 000 in Germany.Objective and Hypotheses: We hypothesize that monogenic alterations might contribute to early-onset insulin secretion defects, if islet function was challenged by obesity-associated insulin resistance.Method: We follow more than 1500 children and adolescents with obesity. Patients...

Background: Recently, mutations in the maternally imprinted MKRN3 gene have been associated to familial idiopathic central precocious puberty (iPPC). The clinical phenotype and the frequency of these mutations are poorly described.Objective and hypotheses: Delineate the frequency of MKRN3 mutations in iPPC and perform a genotype–phenotype correlation in MKRN3 mutated patients.Method: 59 index cases with iPPC have been included...

Background: Mutations in more than 20 genes are described to cause monogenic diabetes. Nevertheless, numerous families with diabetes of unknown ethology and suspected genetic defect have no molecular diagnosis. This not only impedes our understanding of disease mechanisms but also prevents from predicting the clinical course of the patients and applying the pathogenesis-oriented treatment.Objective: To identify novel gene(s), causing monogenic adolescent...

Background: Osteogenesis imperfecta (OI) is a clinically and genetically heterogeneous rare disorder characterized by variable symptoms including predisposition to fractures. OI has been associated with mutations affecting the synthesis of type I collagen. However, the new technologies have permitted the identification of other responsible genes which are in the collagen metabolic pathway, while others are not.Objective: Characterize the genotype of pati...