A novel CHD7 mutation in an adolescent presenting with growth and pubertal delay.

Mutations in the CHD7 gene, encoding for the chromodomain helicase DNA-binding protein 7, are found in approximately 60% of individuals with CHARGE syndrome (coloboma, heart defects, choanal atresia, retarded growth and development, genital hypoplasia, ear abnormalities and/or hearing loss). Herein, we present a clinical case of a 14-year-old male presenting for evaluation of poor growth and pubertal delay highlighting the diagnostic challenges of CHARGE syndrome. The patient was born full term and underwent surgery at 5 days of life for bilateral choanal atresia. Developmental milestones were normally achieved. At age 14 his height and weight were -2.04 and -1.74 standard deviation score respectively. He had anosmia as well as prepubertal testes and micropenis (4 cm×1 cm). The biological profile showed low basal serum testosterone and gonadotropins (testosterone, 0.2 nmol/L; luteinizing hormone, 0.5 U/L; follicle-stimulating hormone, 1.3 U/L), and otherwise normal pituitary function and normal imaging of the hypothalamic-pituitary area. The constellation of choanal atresia, anosmia, mild dysmorphic features, micropenis and delayed puberty were suggestive of CHARGE syndrome. Targeted genetic testing of CHD7 was performed revealing a de novo heterozygous CHD7 mutation (c.4234T>G [p.Tyr1412Asp]). Further paraclinical investigations confirmed CHARGE syndrome. Despite the presence of suggestive features, CHARGE syndrome remained undiagnosed in this patient until adolescence. Genetic testing helps clarify the phenotypic and genotypic spectrum to facilitate diagnosis, thus promoting optimal follow-up, treatment, and appropriate genetic counselling

Congenital hypogonadotropic hypogonadism and constitutional delay of growth and puberty have distinct genetic architectures

Congenital hypogonadotropic hypogonadism (CHH) and constitutional delay of growth and puberty (CDGP) represent rare and common forms of GnRH deficiency, respectively. Both CDGP and CHH present with delayed puberty, and the distinction between these two entities during early adolescence is challenging. More than 30 genes have been implicated in CHH, while the genetic basis of CDGP is poorly understood. We characterized and compared the genetic architectures of CHH and CDGP, to test the hypothesis of a shared genetic basis between these disorders. Exome sequencing data were used to identify rare variants in known genes in CHH ( <i>n</i>  = 116), CDGP ( <i>n</i>  = 72) and control cohorts ( <i>n</i>  = 36 874 ExAC and <i>n</i>  = 405 CoLaus). Mutations in at least one CHH gene were found in 51% of CHH probands, which is significantly higher than in CDGP (7%, <i>P</i>  = 7.6 × 10 <sup>-11</sup> ) or controls (18%, <i>P</i>  = 5.5 × 10 <sup>-12</sup> ). Similarly, oligogenicity (defined as mutations in more than one gene) was common in CHH patients (15%) relative to CDGP (1.4%, <i>P</i>  = 0.002) and controls (2%, <i>P</i>  = 6.4 × 10 <sup>-7</sup> ). Our data suggest that CDGP and CHH have distinct genetic profiles, and this finding may facilitate the differential diagnosis in patients presenting with delayed puberty

Two missense mutations in KCNQ1 cause pituitary hormone deficiency and maternally inherited gingival fibromatosis

Familial growth hormone deficiency provides an opportunity to identify new genetic causes of short stature. Here we combine linkage analysis with whole-genome resequencing in patients with growth hormone deficiency and maternally inherited gingival fibromatosis. We report that patients from three unrelated families harbor either of two missense mutations, c.347G>T p.(Arg116Leu) or c.1106C>T p.(Pro369Leu), in KCNQ1, a gene previously implicated in the long QT interval syndrome. Kcnq1 is expressed in hypothalamic GHRH neurons and pituitary somatotropes. Co-expressing KCNQ1 with the KCNE2 β-subunit shows that both KCNQ1 mutants increase current levels in patch clamp analyses and are associated with reduced pituitary hormone secretion from AtT-20 cells. In conclusion, our results reveal a role for the KCNQ1 potassium channel in the regulation of human growth, and show that growth hormone deficiency associated with maternally inherited gingival fibromatosis is an allelic disorder with cardiac arrhythmia syndromes caused by KCNQ1 mutations

Deciphering the functional role of spatial and temporal muscle synergies in whole-body movements

International audienceVoluntary movement is hypothesized to rely on a limited number of muscle synergies, the recruitment of which translates task goals into effective muscle activity. In this study, we investigated how to analytically characterize the functional role of different types of muscle synergies in task performance. To this end, we recorded a comprehensive dataset of muscle activity during a variety of whole-body pointing movements. We decomposed the electromyographic (EMG) signals using a space-by-time modularity model which encompasses the main types of synergies. We then used a task decoding and information theoretic analysis to probe the role of each synergy by mapping it to specific task features. We found that the temporal and spatial aspects of the movements were encoded by different temporal and spatial muscle synergies, respectively, consistent with the intuition that there should a correspondence between major attributes of movement and major features of synergies. This approach led to the development of a novel computational method for comparing muscle synergies from different participants according to their functional role. This functional similarity analysis yielded a small set of temporal and spatial synergies that describes the main features of whole-body reaching movements

Les maladies auto-immunes de la glande thyroide chez l'enfant. [Autoimmune thyroid disease in children]

Autoimmune thyroid disease in children includes Hashimoto thyroiditis and Graves' disease or toxic diffuse goitre. The immunological mechanisms involved in these diseases are closely related while the clinical picture differs because of the specific type of immunological response that occurs. Both conditions are connected together by their similar thyroid pathology, co-occurrence in family and within the same individual over time. A background inherited predisposition to autoimmunity with additional environmental and hormonal factors contributes to the development of the diseases. These observations help understand their key clinical features as well as their diagnostic and therapeutic approaches

Genetic testing in patients with obesity.

The obesity epidemic is associated with the recent availability of highly palatable and inexpensive caloric food as well as important changes in lifestyle. Genetic factors, however, play a key role in regulating energy balance and numerous twin studies have estimated the BMI heritability between 40 and 70%. While common variants, identified through genome-wide association studies (GWAS) point toward new pathways, their effect size are too low to be of any use in the clinic. This review therefore concentrates on genes and genomic regions associated with very high risks of human obesity. Although there are no consensus guidelines, we review how the knowledge on these "causal factors" can be translated into the clinic for diagnostic purposes. We propose genetic workups guided by clinical manifestations in patients with severe early-onset obesity. While etiological diagnoses are unequivocal in a minority of patients, new genomic tools such as Comparative Genomic Hybridization (CGH) array, have allowed the identification of novel "causal" loci and next-generation sequencing brings the promise of accelerated pace for discoveries relevant to clinical practice

Prise en charge des jeunes patients avec endocrinopathies pediatriques chroniques: les défis d'une transition souvent difficile [Caring for patients with pediatric endocrinopathies and diabetes into adulthood: challenges of an often difficult transition].

The success of therapies for a number of pediatric disorders has posed new challenges for the long-term follow-up of adolescents with chronic endocrinopathies. Unfortunately, too many patients are lost during the transfer from pediatric to adult clinics. The transition process should be well-organized and include the young person and family. Recognizing the special needs of these adolescents is an important step in developing patient-centered approaches to care that enable patients to develop autonomy and self care skills. Key elements in this process include structured policies and guidelines, communication and close collaboration between pediatric and adult clinics, and integrating nurse clinicians in the transition process to help close the gaps in care

Diabète de l'enfant, de l'insulino- vers l'immunothérapie: une prise en charge globale du présent vers le futur [Current and future care for diabetes in children: from insulin to immunotherapy]

Diabetes type I (DTI) is an autoimmune disease characterized by a progressive destruction of the insulin producing beta cells of the pancreas that requires insulin substitution therapy. Recent epidemiological data show an annual increase of the incidence of DTI of 3.9%. Children with new onset diabetes typically present with polyuria, polydipsia and weight loss. As of today no cure for DTI exists. However new therapeutic immunomodulary approaches are under investigation. In the meantime adherence to insulin therapy is mandatory to achieve near physiological glucose levels. Monogenic forms of diabetes remain rare in children, but their diagnosis is important in order to propose a specific treatment. A critical period for the diabetic patient is the transition from pediatric to adult care