OBJECTIVE—Permanent neonatal diabetes (PND) is defined by chronic hyperglycemia due to severe nonautoimmune insulin deficiency diagnosed in the first months of life. Several genes, including KCNJ11 and ABCC8, which encode the two subunits of the ATP-sensitive K+ channel (KATP channel) can cause PND. Mutations in the insulin (INS) gene have been recently described in families with neonatal diabetes. Our study aimed to investigate the genetic anomalies and clinical heterogeneity in PND patients who are negative for a KATP channel mutation. RESEARCH DESIGN AND METHODS—We screened the INS gene by direct sequencing in 38 PND patients and in one child with nonautoimmune early-infancy diabetes, where no mutation in GCK, KCNJ11, and ABCC8 was identified. A detailed clinical phenotyping of the patients was carried out to specify the diabetes features in those found with an INS mutation. RESULTS—We identified three missense mutations in the INS gene in four probands. Two of four mutations were inherited in a dominant manner, and the familial description evidenced a marked variability in age of diagnosis and disease progression. In our cohort, the INS mutations may represent ∼10% of all permanent neonatal diabetes cases, having a later presentation of diabetes and no associated symptoms compared with cases with KATP channel mutations. CONCLUSIONS—Heterozygous INS gene mutations can cause isolated permanent early-infancy diabetes and should be assessed in neonatal as well as in childhood diabetes appearing like type 1, when autoimmune markers are absent. New pharmacogenomic strategies may be applicable, since residual β-cell function is still present in some patients.
From 1991 to 1993, 90 children having received a kidney graft with a post-transplantation period of at least 12 months were included in a prospective study carried out in 18 French pediatric centers. After informed consent and randomization, children received recombinant human growth hormone (rhGH) (Genotonorm, Pharmacia peptide hormones) 30 U/m2 per week, either immediately on enrollment, for the treated group, or after 1 year of follow-up for the group serving as a control. After 1 year both groups were treated and we analyzed data during the subsequent years. Eighty-five children completed the 1-year study. Growth velocity was significantly increased by rhGH: 7.7 cm with a gain of +0.3 standard deviation score in the treated group versus 4.6 cm in the control group (P<0.0001) during the 1st year. Four factors predicted response to therapy: growth velocity prior to GH therapy, glomerular filtration rate (GFR) at the start, mode of corticosteroid administration, and degree of insulin resistance. After 1 year we observed a moderate, significant decrease in GFR in both groups. Biopsy-proven acute rejection episodes were not significantly more frequent during the 1st year in the group of patients who received rhGH: 9 in 44 versus 4 in 46 patients. The patients who rejected did not differ in terms of age, renal function at the start, and type of immunosuppression, but history of rejection before GH treatment was discriminatory: 6 of 17 children with two or more episodes had a new rejection versus 1 of 22 who had no or only one episode (P=0.01). Glucose tolerance was not modified after 1 year of GH therapy. During the subsequent years of treatment a decrease in growth velocity was noted: 5.9 cm at 2 years, 5.5 at 3 years, and 5.2 cm at 4 years. In conclusion, GH is efficient for improving growth velocity in short transplanted children, inducing clear-cut but limited catch-up growth. The risk of rejection was shown only in patients with a prior history of more than one rejection episode.
At 1 year after the severe TBI, pituitary dysfunction was found in 8% of our study sample. We recommend systematic hormonal assessment in children and adolescents 12 months after a severe TBI and prolonged clinical endocrine follow-up.
Forty-two children, aged 2-21.5 years on hemodialysis with a height below -2.0 standard deviation score (SDS) for age, were selected to receive recombinant human growth hormone (rhGH) therapy at 17 French centers. Of the 42 children, 36 were prepubertal and 8 were in early puberty (testicular volume between 4 and 8 ml for boys, breast development B2 or B3 in girls). All received 1 IU/kg per week by daily subcutaneous injection for 1-5 years. The year before rhGH therapy served as a control period. During the 1st year of treatment, mean growth velocity increased from 3.5 to 7.0 cm/year (P < 0.0001) and was always over 2.5 cm/year. This velocity allowed a catch-up growth of +0.5 height SDS. Neither weight nor the body mass index varied compared with the pretreatment year. No change was observed in urea, creatinine, or glucose tolerance. The mean increment in bone age was 0.9 years. The mean growth velocity decreased over subsequent years (P < 0.0001), but remained higher than the prestudy velocity. A significant negative correlation was observed during the 1st year between the increase in growth velocity and the prestudy velocity (P < 0.0001), with the least gain in patients who had the best spontaneous velocity. Pubertal status had no influence on response to rhGH. No significant side effects were observed during the 103 treatment-years. Five patients developed secondary hyperparathyroidism and 1 suffered from acute pancreatitis, but the relationship with rhGH therapy remains uncertain. rhGH therapy appears indicated for children on hemodialysis, even though the potential benefits appear somewhat lower for those with a spontaneous growth velocity over 6 cm/year.
Fetal male sexual differentiation is driven by two testicular hormones: testosterone (synthesized by interstitial Leydig cells) and antimüllerian hormone (AMH; produced by Sertoli cells present in the seminiferous tubules). Intersex states result either from gonadal dysgenesis, in which both Leydig and Sertoli cell populations are affected, or from impaired secretion or action of either testosterone or AMH. Until now, only Leydig cell function has been assessed in children with ambiguous genitalia, by means of testosterone assay. To determine whether serum AMH would help in the diagnosis of intersex conditions, we assayed serum AMH levels in 107 patients with ambiguous genitalia of various etiologies. In XY patients, AMH was low when the intersex condition was caused by abnormal testicular determination (including pure and partial gonadal dysgenesis) but was normal or elevated in patients with impaired testosterone secretion, whereas serum testosterone was low in both groups. AMH was also elevated during the first year of life and at puberty in intersex states caused by androgen insensitivity. In 46,XX patients with a normal male phenotype or ambiguous genitalia, in whom the diagnosis of female pseudohermaphroditism had been excluded, serum AMH levels higher than 75 pmol/L were indicative of the presence of testicular tissue and correlated with the mass of functional testicular parenchyma. In conclusion, serum AMH determination is a powerful tool to assess Sertoli cell function in children with intersex states, and it helps to distinguish between defects of male sexual differentiation caused by abnormal testicular determination and those resulting from isolated impairment of testosterone secretion or action.
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