Early age at menarche: a risk factor for overweight or obesity in patients with type 1 diabetes living in urban areas?

AIMS: Determine the relationship between age at menarche, glycemic control and cardiovascular risk factors in patients with type 1 diabetes living in urban areas. METHODS: This was a multicenter cross-sectional study conducted in 20 cities in four Brazilian geographic regions. Data were obtained from 1527 female patients, 59.3% Caucasians, aged 25.1 ± 10.6 years. Diabetes duration was 11.4 ± 8.1 years. Age at menarche was stratified in four groups: 8-11 (group 1, early menarche), 12 (group 2), 13 (group 3) and 14-18 years (group 4, late menarche). RESULTS: The mean age at menarche was 12.7 ± 1.7 years without difference among geographical regions, economic status, level of care and ethnicity. BMI had an inverse correlation with age at menarche (r=-0.14, p<0.001). No significant difference was observed among the four groups for blood pressure, lipid profile and diabetes-related chronic complications. Logistic regression analysis showed that early age at menarche, 8-11 years (odds ratio (ORs) 1.77 [1.30-2.41], p<0.001) and duration of diabetes [ORs 1.01 (1.00-1.03), p=0.02], were related to greater risk of patients' overweight or obesity; adherence to diet [ORs 0.78 (0.60-0.93), p=0.01], physical activity [ORs 0.75 (0.94-0.94), p=0.01], and lower insulin dose (U/kg) [ORs 0.54 (0.59-0.90), p=0.001] were related to lower risk for overweight or obesity. CONCLUSIONS: Early menarche occurred in 23.4% of women with type 1 diabetes living in Brazilian urban areas and was strongly associated with overweight/obesity in pubertal/adult life. Further studies are warranted to establish the relationship between early menarche, glycemic control and cardiovascular risk factors.

First two years' response to growth hormone treatment in very young preterm small for gestational age children.

BACKGROUND: Growth hormone (GH) is a therapeutic option for small for gestational age (SGA) children without spontaneous catch-up. There are few reports on preterm SGA children. Prematurity is an additional risk factor for adult short stature. AIM: To describe GH efficacy in preterm SGA patients. METHODS: Twenty-five preterm SGA patients, 2-4 years old, treated with GH 0.066 mg/kg/day, were compared with 14 age-matched preterm SGA historical controls. Height, weight, IGF-I, IGFBP-3, fasting glucose and insulin were measured every 6 months. RESULTS: At start of GH treatment, mean height and weight were -2.4 and -2.4 SDS, respectively. There was a significant increment in height SDS of 1.3 and 2.1 during the 1st and the 2nd year of GH therapy, respectively. There was no significant difference between the progression of chronological and bone ages. A significant increase in IGF-I, IGFBP-3 and molar ratio was observed during GH therapy. There was no difference in glucose, insulin or HOMA-IR index. CONCLUSION: We showed for the first time that the height increment of preterm SGA with GH treatment is similar to that described in other studies with term SGA patients. Therefore, short-term GH treatment in a subset of preterm SGA patients between 2-4 years of age was able to promote adequate growth recovery with no excessive bone age acceleration or adverse effects on carbohydrate metabolism.

Size of the exon 1-CAG repeats of the androgen receptor gene employed as a molecular marker in the diagnosis of Turner syndrome in girls with short stature.

Turner syndrome (TS) is one of the most common chromosomal abnormalities among girls. Complete monosomy of X chromosome is responsible for almost 50% of all cases of TS, and mosaicism and X anomaly are detected in the other half. It has already been demonstrated that early diagnosis of these children allows appropriate growth hormone treatment with better final height prognosis and introduction of estrogen at an ideal chronological age. Sixty-four short-stature girls were selected and the clinical data obtained were birth weight and height, weight and height at the first medical visit and target height. Other clinical data including cardiac and renal abnormalities, otitis, Hashimoto thyroiditis, cubitus valgus, short neck, widely separated nipples, and pigmented nevi were obtained from the patients' medical records. The aim of the present study was to evaluate the screening of a group of short-stature girls for TS based on the number of CAG repeats of the androgen receptor gene analyzed by GeneScan software. Patient samples with two alleles (heterozygous) were 49/64 (76.5%) and with one allele (homozygous) were 15/64 (23.5%). A karyotype was determined in 30 patients, 9 homozygous and 21 heterozygous. In the homozygous group, 6/9 were 45,X and 3/9 were 46,XX. In the heterozygous group, 17/21 were 46,XX, and 4/21 were TS patients with mosaicism (45,X/46,XX; 45,X/46XiXq; 46XdelXp). The pattern obtained by GeneScan in two patients with mosaicism in the karyotype was an imbalance between the peak heights of the two alleles, suggesting that this imbalance could be present when there is a mosaicism. The frequency of TS abnormalities (18.7%) did not differ between TS and 46,XX girls. Thus, it is important to accurately assess the incidence of TS in growth-retarded girls, even in the absence of other dysmorphisms. In this study, we diagnosed 6 cases of TS 45,X (9.4%) by molecular analysis, with a 100% sensitivity and 85% specificity. This molecular analysis was able to detect all cases of TS 45,X and the majority of mosaicisms, without the need for more X chromosome markers. In conclusion, determining the number of CAG repeats of the androgen receptor gene analyzed by GeneScan was a fast method with high sensitivity for the detection of TS 45,X, suggesting that it could be interesting as a method for screening a population of growth-retarded girls.

Size of the exon 1-CAG repeats of the androgen receptor gene employed as a molecular marker in the diagnosis of Turner syndrome in girls with short stature

Turner syndrome (TS) is one of the most common chromosomal abnormalities among girls. Complete monosomy of X chromosome is responsible for almost 50% of all cases of TS, and mosaicism and X anomaly are detected in the other half. It has already been demonstrated that early diagnosis of these children allows appropriate growth hormone treatment with better final height prognosis and introduction of estrogen at an ideal chronological age. Sixty-four short-stature girls were selected and the clinical data obtained were birth weight and height, weight and height at the first medical visit and target height. Other clinical data including cardiac and renal abnormalities, otitis, Hashimoto thyroiditis, cubitus valgus, short neck, widely separated nipples, and pigmented nevi were obtained from the patients’ medical records. The aim of the present study was to evaluate the screening of a group of short-stature girls for TS based on the number of CAG repeats of the androgen receptor gene analyzed by GeneScan software. Patient samples with two alleles (heterozygous) were 49/64 (76.5%) and with one allele (homozygous) were 15/64 (23.5%). A karyotype was determined in 30 patients, 9 homozygous and 21 heterozygous. In the homozygous group, 6/9 were 45,X and 3/9 were 46,XX. In the heterozygous group, 17/21 were 46,XX, and 4/21 were TS patients with mosaicism (45,X/46,XX; 45,X/46XiXq; 46XdelXp). The pattern obtained by GeneScan in two patients with mosaicism in the karyotype was an imbalance between the peak heights of the two alleles, suggesting that this imbalance could be present when there is a mosaicism. The frequency of TS abnormalities (18.7%) did not differ between TS and 46,XX girls. Thus, it is important to accurately assess the incidence of TS in growth-retarded girls, even in the absence of other dysmorphisms. In this study, we diagnosed 6 cases of TS 45,X (9.4%) by molecular analysis, with a 100% sensitivity and 85% specificity. This molecular analysis was...

A novel mutation in DAX1 gene causing different phenotypes in three siblings with adrenal hypoplasia congenita.

Adrenal hypoplasia congenita (AHC) is a rare disease that can be caused by many abnormalities, including an X-linked form. Mutations in the DAX1 gene have been assigned as the genetic cause of AHC. We describe here three siblings with AHC, clinically presented at different ages, two in the neonatal period and one oligosymptomatic during infancy. Molecular analysis was able to detect a novel mutation in exon 1 of the DAX1 gene, consisting of a transition of C to T at position 359, determining a stop codon at position 359 (Q359X). The mutated gene encodes a truncated protein missing a large portion of the ligand-binding domain (C-terminal domain). The recognition of the disease in the index case suggested the diagnosis in the other siblings. Interestingly, the same mutation is presented with different phenotypes, suggesting that first-degree family members of patients with DAX1 mutations should be carefully evaluated routinely.

The influence of parental origin of X chromosome genes on the stature of patients with 45 X Turner syndrome.

Thirty-seven 45 X Turner syndrome patients with confirmed peripheral blood lymphocyte karyotype were initially selected to determine the origin of the retained X chromosome and to correlate it with their parents' stature. Blood samples were available in 25 families. The parental origin of the X chromosome was determined in 24 informative families through the analysis of the exon 1-CAG repeat variation of the androgen receptor gene. In 70.8% of the cases, the retained X chromosome was maternal in origin and 29.2% was paternal. When we classified the patients according to maternal (Xm) or paternal (Xp) X chromosome, there was a positive correlation between patients' and maternal heights only in the Xm group. There was no correlation with paternal height in either group, and a significant correlation with target height was only observed in the Xm group. In conclusion, maternal height is the best variable correlating with the height of 45 X Turner syndrome patients who retain the maternal X chromosome, suggesting a strong influence of genes located on the maternal X chromosome on stature.

The influence of parental origin of X chromosome genes on the stature of patients with 45 X Turner syndrome

Thirty-seven 45 X Turner syndrome patients with confirmed peripheral blood lymphocyte karyotype were initially selected to determine the origin of the retained X chromosome and to correlate it with their parents’ stature. Blood samples were available in 25 families. The parental origin of the X chromosome was determined in 24 informativefamilies through the analysis of the exon 1 - CAG repeat variation of the androgen receptor gene. In 70.8% of the cases, the retained X chromosome was maternal in origin and 29.2% was paternal. When we classified the patients according to maternal (Xm) or paternal (Xp) X chromosome, there was a positive correlation between patients’ and maternal heights only in the Xm group. There was no correlation with paternal height in either group, and a significant correlation with target height was only observed in the Xm group. In conclusion, maternal height is the best variable correlating with the height of 45 X Turner syndrome patients who retain the maternal X chromosome, suggesting a strong influence of genes located on the maternal X chromosome on stature.

Inhibin alpha-subunit (INHA) gene and locus changes in paediatric adrenocortical tumours from TP53 R337H mutation heterozygote carriers.

The R337H TP53 mutation is a low-penetrance molecular defect that predisposes to adrenocortical tumour (ACT) formation in Brazilian and possibly other populations. Additional genetic defects may be responsible for the variable expression of ACTs in these cases. The inhibin alpha-subunit gene (INHA) on 2q33-qter has been implicated in mouse adrenocortical tumourigenesis. We studied 46 pediatric patients with ACTs from Brazil for INHA genetic alterations; 39 of these patients were heterozygous carriers of the R337H TP53 mutation. We first mapped the INHA gene by radiation hybrid analysis and determined 10 linked microsatellite markers in an area flanked by D2S1371 and D2S206 on 2q33-qter. These markers were then used for loss of heterozygozity (LOH) studies in nine paired germline and tumour DNA samples. Mapping placed the INHA gene in close proximity to D2S2848 (SHGC11864) with a log of odds (LOD) score of 5.84. LOH for at least one marker in the region was identified in 8/9 tumours (89%). Six patients were heterozygous for three INHA mutations: one in exon 1, 127C>G, and two in exon 2, 3998G>A and 4088G>A, all leading to amino acid substitutions (P43A, G227R, and A257T, respectively). A257T is located in a conserved INHA region, highly homologous to transforming growth factor-beta; both G227R and A257T change polarity, and, in addition, G227R changes the pH. We conclude that these sequence alterations and the detected 2q allelic changes suggest that INHA may be one of the contributing factors needed for ACT formation in pediatric patient carriers of the R337H TP53 mutation.