Adherence to treatment in children with growth hormone deficiency, small for gestational age and Turner syndrome in Mexico: results of the Easypod™ connect observational study (ECOS).

BACKGROUND: Assessing adherence to growth hormone (GH) is challenging. The Easypod™ connect device delivers pre-set doses of recombinant human GH (r-hGH) and stores a digital record of adherence that can be shared with healthcare provider. We assessed adherence to r-hGH delivered with Easypod™ according to the approved pediatric indications for r-hGH: growth hormone deficiency (GHD), born small for gestational age (SGA) who failed to show catch-up growth and Turner syndrome (TS). METHODS: ECOS (NCT01555528) was a multicenter (24 countries), 5-year, longitudinal, observational study, which aimed to evaluate country-specific adherence to r-hGH therapy prescribed via the Easypod™ electronic injection device. The primary endpoint was yearly adherence. Secondary endpoints were height velocity, height velocity standard deviation scores (SDS), height, height SDS and IGF-1 concentrations. Clinical and auxological data were obtained from medical records and adherence from Easypod™ logs. RESULTS: This study included 147 Easypod™-naïve Mexican children assessed during 3 years (mean age: 9.96 ± 3.41 years, 56.8% boys, mean height SDS at baseline: - 2.17 ± 0.97): 118 with GHD, 24 SGA and 5 with TS. A total of 105 (71.4%) patients were GH naïve. Overall median adherence was > 90% over the first year of treatment and > 80% at 3 years. Adherence was not different by r-hGH indication or between GH-naïve or experienced patients. At 1-year follow-up, mean change in height SDS was 0.57 ± 0.34, whereas mean height velocity SDS was 2.85 ± 2.51. In all, 84.7% patients had normal IGF-1 concentrations at 1-year follow-up. Adherence was associated with change in height SDS (r = 0.239, p = 0.005) and height velocity SDS (r = 0.194, p = 0.027). CONCLUSION: Adherence rates with the Easypod™ device are high and maintained over time in GHD, SGA and TS Easypod™-naïve Mexican patients. High adherence is associated with better outcomes. Easypod™ assists physicians in monitoring adherence to r-hGH.

Evidence that steroid 5alpha-reductase isozyme genes are differentially methylated in human lymphocytes.

The synthesis of dihydrotestosterone (DHT) is catalyzed by steroid 5alpha-reductase isozymes 1 and 2, and this function determines the development of the male phenotype during embriogenesis and the growth of androgen sensitive tissues during puberty. The aim of this study was to determine the cytosine methylation status of 5alpha-reductase isozymes types 1 and 2 genes in normal and in 5alpha-reductase deficient men. Genomic DNA was obtained from lymphocytes of both normal subjects and patients with primary 5alpha-reductase deficiency due to point mutations in 5alpha-reductase 2 gene. Southern blot analysis of 5alpha-reductase types 1 and 2 genes from DNA samples digested with HpaII presented a different cytosine methylation pattern compared to that observed with its isoschizomer MspI, indicating that both genes are methylated in CCGG sequences. The analysis of 5alpha-reductase 1 gene from DNA samples digested with Sau3AI and its isoschizomer MboI which recognize methylation in GATC sequences showed an identical methylation pattern. In contrast, 5alpha-reductase 2 gene digested with Sau3AI presented a different methylation pattern to that of the samples digested with MboI, indicating that steroid 5alpha-reductase 2 gene possess methylated cytosines in GATC sequences. Analysis of exon 4 of 5alpha-reductase 2 gene after metabisulfite PCR showed that normal and deficient subjects present a different methylation pattern, being more methylated in patients with 5alpha-reductase 2 mutated gene. The overall results suggest that 5alpha-reductase genes 1 and 2 are differentially methylated in lymphocytes from normal and 5alpha-reductase deficient patients. Moreover, the extensive cytosine methylation pattern observed in exon 4 of 5alpha-reductase 2 gene in deficient patients, points out to an increased rate of mutations in this gene.

Longitudinal assessment of L-T4 therapy for congenital hypothyroidism: differences between athyreosis vs ectopia and delayed vs normal bone age.

To study the effects of LT4 dose on thyroid hormone serum levels, a prospective, longitudinal and comparative study was designed, including 56 term eutrophic 1-89 day-old infants with congenital hypothyroidism (CH) detected by neonatal screening. Patients were divided into four groups according to delayed or normal bone age at birth, and athyreosis or ectopic thyroid. All received an initial dose of 50 micrograms/day (12.9-13.7 micrograms/kg/day) LT4 and were followed bimonthly (first year) and quarterly (second year) with thyroid profile and bone age determinations at 6, 12 and 24 months. At diagnosis, hormone levels were higher in cases of ectopia than in athyreosis (p < 0.001), and T4 was lower in children with delayed than in normal bone age at birth (p < 0.05). During treatment, all groups were clinically euthyroid despite T4 and FT4 serum levels higher than the upper normal limit (p < 0.0.001), though T3 and FT3 were within the normal limit (p > 0.05). TSH normalized within 8 weeks. Bone age accelerated at 2 years in eight children of the bone age delayed group. No patient had craniosynostosis.

Molecular genetic analysis of patients carrying steroid 21-hydroxylase deficiency in the Mexican population: identification of possible new mutations and high prevalence of apparent germ-line mutations.

Steroid 21-hydroxylase deficiency is the underlying cause in over 90% of patients with congenital adrenal hyperplasia, an inherited metabolic disorder of adrenal steroidogenesis. We have characterized 94 mutant alleles from 47 unrelated Mexican patients and the corresponding mutant alleles in their parents by amplification of the functional CYP21 gene by PCR, followed by direct sequence analysis. The study included patients diagnosed with the three clinical forms of the disease. Our results revealed: (1) the presence of relatively few mutations or combinations of mutations associated with particular phenotypes; (2) the presence of putative new mutations; (3) the finding of identical genotypes in patients displaying discordant phenotypes; (4) the identification of patients lacking all previous reported mutations; and (5) an apparent high frequency of germ-line mutations. The absence of previously reported mutations in about 22% of the disease alleles, the finding of putative new mutations in some of the patients lacking previously known mutations, and the apparent high prevalence of germ-line mutations make evident the differences in the genetic background leading to this disorder between the Caucasian and the Mexican populations.

Analysis of the glucokinase gene in Mexican families displaying early-onset non-insulin-dependent diabetes mellitus including MODY families.

Non-insulin-dependent diabetes mellitus (NIDDM) is the most common form of diabetes, affecting 5% of the general population. Genetic factors play an important role in the development of the disease. While in other populations NIDDM is usually diagnosed after the fifth decade of life, in Mexico a large proportion of patients develop the disease at an early age (between the third and the fourth decade). In Caucasian population, mutations in the glucokinase gene, the TCF1, and TCF14 genes, have been identified in a subgroup of early-onset NIDDM patients denominated MODY (maturity-onset diabetes of the young), which show an autosomal dominant pattern of inheritance. As a first step in the molecular characterization of Mexican families displaying early-onset NIDDM we searched for mutations in the glucokinase gene through SSCP analysis and/or direct sequencing in 26 individuals from 22 independent families, where at least four can be classified as MODY. No mutations were detected in the exons or the intron-exon boundaries of the gene in any of the screened individuals. The phenotype and clinical profile of some of the studied patients is compatible with that of patients carrying mutations in the TCF1 or TCF14 genes, while others may carry mutations in different loci. Through computer simulation analysis we identified at least four informative families which will be used for further linkage studies.

Fasting and postprandial serum insulin in Mexican adolescents with menstrual disorders.

PURPOSE: To investigate insulin serum concentrations in basal and stimulated conditions in a group of Mexican adolescents presenting menstrual disturbances. METHODS: A total of 77 post-menarchial adolescents were studied: 65 with a chronological age of 15 +/- 1.7 years (mean +/- SD) had persistent anovulation and represented the study group; 12 were normal ovulatory adolescents (15 +/- 1.2 years) and served as controls. Body mass index (BMI), waist to hip ratio (W/H), presence and severity of acne, hirsutism, acanthosis nigricans (AN) and follicular hyperkeratosis were recorded. Transabdominal pelvic ultrasound was performed and LH, FSH, estradiol, prolactin, testosterone, androstenedione and sex hormone binding globulin (SHBG) concentrations were measured in plasma by specific immunoassays. Glucose and insulin levels were determined in venous blood following an overnight fasting and two hours after a standardized breakfast. RESULTS: Anovulatory patients were divided in three groups depending on the presence of AN and overweight (BMI > 25). The insulin concentration in the study patients were remarkably higher than the values reported in the medical literature. Statistically significant differences were also found in fasting and postprandial insulin concentrations among the three anovulatory groups. Insulin values correlated with the severity of AN, W/H ratio, BMI and SHBG serum levels. CONCLUSIONS: Our study indicates that moderate to severe hyperinsulinemia is present in a high proportion of our adolescent anovulatory population. Whether hyperinsulinemia represents a transitory peripubertal event or is a predictive marker of chronic anovulation and metabolic derangement in adult life needs further investigation.

Low frequency of deletion alleles in patients with steroid 21-hydroxylase deficiency in a Mexican population.

Steroid 21-hydroxylase deficiency is caused by mutations in the CYP21 gene. Approximately 95% of mutant alleles are generated by recombination events between the active gene CYP21 and its highly homologous pseudogene, CYP21P. Deletion alleles are generated by unequal crossing over, while point mutations are the result of gene conversion events. Deletions account for 20-25% of the 21-hydroxylase deficiency alleles in most populations studied. We have looked for deletions among 53 unrelated Mexican patients with steroid 21-hydroxylase deficiency and found that deletions represent less than 1% of the disease alleles. These findings suggest that nearly all mutant alleles in our patient population contain point mutations and that the low representation of deletion alleles among clinically diagnosed patients may be due to missing detection of salt wasters, mainly males, who may die during the neonatal period.

Anticuerpos antitiroideos en hipotiroidismo congénito / Antithyroid antibodies in congenital hypothyroidism

El papel que los anticuerpos antitiroideos maternos pueden desempeñar en la etiopatogenia del hipotiroidismo congénito por atireosis es discutible. En este estudio se midieron los niveles séricos de antivuerpos antitiroideos en 12 pacientes hipotiroideos y en sus madres, con la finalidad de detectar la posible asociación entre enfermedad tiroidea autoinmune materna y displasia tiroidea fetal. En dos pacientes hubo anticuerpos antitiroglobulina, lo que apoya la teoría de la existencia de un proceso inmunológico contra la tiroides fetal en las primeras ocho semanas de festación, pero no descarta la existencia y/o coexistencia de otros factores etiopatogénicos

[Biosynthetic growth hormone extracted from mammalian cells used in the management of growth hormone deficient children]. / Hormona de crecimiento biosintética, extraída de células de mamífero en el manejo de niños con deficiencia de hormona de crecimiento.

Biosynthetic growth hormone extracted from mammalian cells was used in eight children with growth hormone deficiency, in search for a clinical safety study. Each child received 0.6 U/kg/week, subcutaneously, during a period of six months, and was evaluated monthly for clinical, anthropometric and laboratory modifications induced by the drug in a physiological or pathological way. The growth velocity increased from less that 4 cm/year to 11.2 +/- 1.08 cm/year, the bone age maintained according to the chronological age, and the anthropometric evaluation showed an harmonious and physiological growth. There was not any undesirable nor secondary changes except transient hypothyroidism in two patients, and unmasked hypophyseal hypothyroidism in another two. We concluded that biosynthetic growth hormone extracted from mammalian cells is a safety drug, and that patients with growth hormone deficiency may be treated with it in order to improve their final height expectancy.

[The use of a biosynthetic human growth hormone in children with a growth hormone deficiency]. / Uso de hormona de crecimiento humana biosintética en niños con deficiencia de hormona de crecimiento.

Ten growth hormone deficient patients (GHDP) (six girls & four boys) with chronological age range six-15 years old, received recombinant human growth hormone (GH) (0.6 UI/kg/week) in three subcutaneous injections per week over 14 months. A complete physical examination was performed monthly; thyroid hormones concentrations every two months, as well as, bone age every four months were determined. Growth velocity was higher in the first six months' treatment (12.73 +/- 1.65 cm/yr vs 10.6 +/- 1.67 cm/yr; previous growth velocity 3.76 +/- 2.4 cm/yr). The variables with better prognosis were: lower previous growth velocity, lower chronological age (< 12 ys), lower bone age (< 8 ys), higher BMI than ideal; and higher acid alkaline phosphate during treatment. Two of ours patients developed biochemical hypothyroidism during the treatment period, and they needed hormonal substitutive therapy. With GH treatment a harmonious growth is obtain with bone age progress according chronological age. The height of GHDP treated with GH do not approaches the height range of their parents, probably due the time of treatment. In the follow-up of all patients treated with GH is important to realize periodical laboratories screenings looking for another hypothalamic and/or hypophyseal deficiencies.