High prevalence of variants in skeletal dysplasia associated genes in individuals with short stature and minor skeletal anomalies.

OBJECTIVE: Next generation sequencing (NGS) has expanded the diagnostic paradigm turning the focus to the growth plate. The aim of the study was to determine the prevalence of variants in genes implicated in skeletal dysplasias in probands with short stature and mild skeletal anomalies. DESIGN: Clinical and radiological data were collected from 108 probands with short stature and mild skeletal anomalies. METHODS: A customized skeletal dysplasia NGS panel was performed. Variants were classified using ACMG recommendations and Sherloc. Anthropometric measurements and skeletal anomalies were subsequently compared in those with or without an identified genetic defect. RESULTS: Heterozygous variants were identified in 21/108 probands (19.4%). Variants were most frequently identified in ACAN (n = 10) and IHH (n = 7) whilst one variant was detected in COL2A1, CREBBP, EXT1, and PTPN11. Statistically significant differences (P < 0.05) were observed for sitting height/height (SH/H) ratio, SH/H ratio standard deviation score (SDS), and the SH/H ratio SDS >1 in those with an identified variant compared to those without. CONCLUSIONS: A molecular defect was elucidated in a fifth of patients. Thus, the prevalence of mild forms of skeletal dysplasias is relatively high in individuals with short stature and mild skeletal anomalies, with variants in ACAN and IHH accounting for 81% of the cases. An elevated SH/H ratio appears to be associated with a greater probability in detecting a variant, but no other clinical or radiological feature has been found determinant to finding a genetic cause. Currently, we cannot perform extensive molecular studies in all short stature individuals so detailed clinical and radiological phenotyping may orientate which are the candidate patients to obtain worthwhile results. In addition, detailed phenotyping of probands and family members will often aid variant classification.

Clinical and Molecular Description of 16 Families With Heterozygous IHH Variants.

CONTEXT: Heterozygous variants in the Indian hedgehog gene (IHH) have been reported to cause brachydactyly type A1 and mild hand and feet skeletal anomalies with short stature. Genetic screening in individuals with short stature and mild skeletal anomalies has been increasing over recent years, allowing us to broaden the clinical spectrum of skeletal dysplasias. OBJECTIVE: The objective of this article is to describe the genotype and phenotype of 16 probands with heterozygous variants in IHH. PATIENTS AND METHODS: Targeted next-generation sequencing or Sanger sequencing was performed in patients with short stature and/or brachydactyly for which the genetic cause was unknown. RESULTS: Fifteen different heterozygous IHH variants were detected, one of which is the first reported complete deletion of IHH. None of the patients showed the classical phenotype of brachydactyly type A1. The most frequently observed clinical characteristics were mild to moderate short stature as well as shortening of the middle phalanx on the fifth finger. The identified IHH variants were demonstrated to cosegregate with the short stature and/or brachydactyly in the 13 probands whose family members were available. However, clinical heterogeneity was observed: Two short-statured probands showed no hand radiological anomalies, whereas another 5 were of normal height but had brachydactyly. CONCLUSIONS: Short stature and/or mild skeletal hand defects can be caused by IHH variants. Defects in this gene should be considered in individuals with these findings, especially when there is an autosomal dominant pattern of inheritance. Although no genotype-phenotype correlation was observed, cosegregation studies should be performed and where possible functional characterization before concluding that a variant is causative.

Adherence and long-term outcomes of growth hormone therapy with easypod™ in pediatric subjects: Spanish ECOS study.

BACKGROUND: Non-adherence to r-hGH treatments occurs in a variable percentage of subjects. One problem found when evaluating adherence is the great variability in methods of detection and definitions utilized in studies. This study assessed the level of adherence in subjects receiving r-hGH with the easypod™ electronic device. METHODS: National, multicenter, prospective and observational study involving 238 subjects (144 with GH deficiency (GHD), and 86 with small for gestational age (SGA), 8 with Turner Syndrome), who received r-hGH with easypod™ for at least 3 months before inclusion. The follow-up period was 4 years. RESULTS: Overall adherence was 94.5%; 97.5% after 6 months, 95.3% after 1 year, 93.7% after 2, 94.4% after 3 and 95.5% after 4 years of treatment. No differences in adherence were observed between prepubertal and pubertal groups and GHD and SGA groups. Change in height after 1 and 2 years, change in height SDS after 1 and 2 years, HV after 1 year, HV SDS after at 1 and 4 years, change in BMI after 1 year and change in BMI SDS at 1 and 2 years showed significant correlation with adherence. No significant differences in adherence according to IGF-I levels were found in follow-up visits or between groups. CONCLUSIONS: The easypod™ electronic device, apart from being a precise and objective measure of adherence to r-hGH treatment, allows high compliance rates to be achieved over long periods of time. Adherence significantly impacts growth outcomes associated with r-hGH treatment.

[Incidence of type 1 diabetes mellitus in children: results from the population registry of the Madrid Region, 1997-2005]. / Incidencia de diabetes mellitus tipo 1 en niños: resultados del registro poblacional de la Comunidad de Madrid, 1997-2005.

BACKGROUND AND OBJECTIVE: Incidence of type 1 diabetes mellitus (DM) varies importantly worldwide, including European countries, and even among regions within a country. The aim of this study is to describe the incidence of type 1 DM in the Madrid Region. MATERIAL AND METHOD: We included 1130 new cases of type 1 DM in children below 15 years of age, which were notified to the diabetes registry from January, 1997 to December, 2005. Case ascertainment was evaluated through the capture-recapture method. The data was analysed using Poisson regression models. RESULTS: The incidence rate in this period was 15.9/100,000 persons-years (95% confidence interval, 15.0-16.8). Completeness of ascertainment was 82%. The incidence by age group was 12.1 (0-4 years), 18.2 (5-9 years) and 17.4 by 100,000 persons-years (10-14 years). The incidence data showed no significant changes in the studied period. We observed a seasonal variation in the incidence, with the greatest incidence in the cold months. CONCLUSIONS: The estimated incidence of type 1 DM ranks in an intermediate position with regard to that estimated more recently in other Spanish regions. During the period 1997-2005, the incidence has maintained stable in the Madrid Region.