ESPE Abstracts

Introduction: C-type natriuretic peptide receptor encoded by NPR2 gene stimulates chondrocyte differentiation and hypertrophy and extracellular matrix production within the growth plate. The phenotypical spectrum of NPR2 mutations is broad, from severe autosomal recessive acromesomelic dysplasia to milder autosomal dominant growth disorders. Some children with NPR2 variants are treated with growth hormone (GH), however, with the inco...

Introduction: Estrogens play an essential role in reproduction and their peripheral action is mediated via nuclear alfa and beta receptors (ER) as well as membrane receptors. To date, only 3 females and 2 males from 3 families with a loss of function of ERa have been reported. The phenotype in these families was strongly suggestive of an estrogen resistance with an absence of a complete puberty, a delay in epiphyseal maturation with high estradiol levels and e...

Introduction: Limited, small-scale studies have revealed that men with proximal hypospadias (HS) or with other signs of undermasculinisation (i.e. complex HS) are at risk of reduced fertility and/or impaired testicular hormone synthesis. However, the extent of this phenomenon and if milder forms of isolated HS are also affected, remains unclear.Aims: To explore reproductive hormones and semen quality of young men (16-21 ...

Background: A few patients with NS have been reported to harbour pathogenic mutations in LZTR1 gene. RAS regulation by LZTR1-mediated ubiquitination provides an explanation for the role of LZTR1 in human disease. Mutations in this gene could hence lead to NS phenotype. Three patients with mutations in this gene and compatible NS phenotype are herein described.Case 1: A 5 year-old boy with bilateral cryp...

Background: Defects of the insulin receptor gene (INSR) can cause genetic syndromes associated with a wide diverse range of congenital insulin resistance from milder insulin-resistant diabetes mellitus (Type A insulin resistance syndrome, TAIRS) to leprechaunism (Donahue syndrome). Clinical features in TAIRS vary due to the severity of damage in INSR, precise diagnosis is challenging.Materials and Methods</stron...

Introduction: Our Centre is an international referral centre for genetic analysis of children with short stature (SS) and features of GH/IGF-1 resistance. Following candidate gene and whole exome sequencing, diagnoses for ~50% patients remained elusive. Copy number variation (CNV) has not previously been investigated in GH/IGF-1 resistance and we hypothesised that CNVs contribute to the phenotype in our undiagnosed cohort.Experimental Design and Methodol...

Background: PHA1 is a rare inherited disease characterized by resistance to aldosterone action and distinguished in two forms: the autosomal dominant renal form caused by mutations of the NR3C2 gene (MR) and the autosomal recessive systemic form caused by mutations of the subunit genes SCNN1A, SCNN1B, SCNN1G of the epithelial sodium channel (ENaC). The classic phenotype of the autosomal recessive form of PHA1 is usually severe, lifelong, and expressed with mu...

Congenital adrenal hyperplasia due to P450c21 (21-hydroxylase) deficiency is an autosomal recessive disorder presenting as three phenotypes dependent on the residual enzyme activity: two classical ones (salt wasting and simple virilizing, SV) and the milder NCAH. All forms have increased adrenal androgens. Around 0.1% of Caucasians and up to several percent of certain ethnic groups are affected by NCAH. Most NCAH patients remain undiagnosed. Symptoms of NCAH may develop at any...

Hypophosphatasia is characterized by defective mineralization of bone and/or teeth in the presence of low activity of serum and bone alkaline phosphatase. Clinical features range from stillbirth without mineralized bone at the severe end to pathologic fractures of the lower extremities in later adulthood at the mild end. Although the disease spectrum is a continuum, six clinical forms are usually recognized based on age at diagnosis and severity of features: Perinatal (severe)...

Background: Growth Hormone Insensitivity (GHI) is usually caused by mutations in the Growth Hormone receptor (GHR). Patients present with short stature associated with high GH and low IGF-I levels and often have midfacial hypoplasia (typical Laron syndrome facial features). Our centre previously described the first GHR pseudoexon mutation (42700896A>G, c. 618+792A>G). The inclusion of this 108bp pseudoexon is predicted to lead to in-frame insertion of...