Hiperglicemia incidental em crianças: duas famílias com MODY 2 identificadas em brasileiros

Maturity-onset diabetes of the young (MODY) is characterized by an autosomal dominant mode of inheritance, early onset of hyperglycemia, and defects of insulin secretion. MODY subtypes described present genetic, metabolic, and clinical differences. MODY 2 is characterized by mild asymptomatic fasting hyperglycemia, and rarely requires pharmacological treatment. Hence, precise diagnosis of MODY is important for determining management and prognosis. We report two heterozygous GCK mutations identified during the investigation of short stature. Case 1: a prepubertal 14-year-old boy was evaluated for constitutional delay of growth and puberty. During follow-up, he showed abnormal fasting glucose (113 mg/dL), increased level of HbA1c (6.6%), and negative beta-cell antibodies. His father and two siblings also had slightly elevated blood glucose levels. The mother had normal glycemia. A GCK heterozygous missense mutation, p.Arg191Trp, was identified in the proband. Eighteen family members were screened for this mutation, and 11 had the mutation in heterozygous state. Case 2: a 4-year-old boy investigated for short stature revealed no other laboratorial alterations than elevated glycemia (118 mg/dL); beta-cell antibodies were negative. His father, a paternal aunt, and the paternal grandmother also had slightly elevated glycemia, whereas his mother had normal glycemia. A GCK heterozygous missense mutation, p.Glu221Lys, was identified in the index patient and in four family members. All affected patients had mild elevated glycemia. Individuals with normal glycemia did not harbor mutations. GCK mutation screening should be considered in patients with chronic mild early-onset hyperglycemia, family history of impaired glycemia, and negative beta-cell antibodies. Arq Bras Endocrinol Metab. 2012;56(8):519-24O diabetes do tipo MODY (maturity-onset diabetes of the young) caracteriza-se por herança autossômica dominante, início precoce da hiperglicemia e defeitos na secreção de insulina. Os subtipos de MODY apresentam diferenças genéticas, metabólicas e clínicas. O MODY 2 é caracterizado por hiperglicemia leve assintomática e raramente requer tratamento farmacológico. O diagnóstico preciso de MODY é importante para se determinar o tratamento e o prognóstico. Relatamos duas mutações no gene GCK em heterozigose identificadas durante investigação de baixa estatura. Caso 1: paciente do sexo masculino, com 14 anos, pré-púbere, avaliado por atraso constitucional do crescimento e da puberdade. Durante o acompanhamento, apresentou glicemia de jejum alterada (113 mg/dL), aumento de HbA1c (6,6%) e anticorpos anticélulas β negativos. Seu pai e dois irmãos também apresentavam glicemia levemente elevada. A mãe tinha glicemia normal. Foi identificada no gene GCK uma mutação missense em heterozigose, p.Arg191Trp. Dezoito membros da família foram rastreados e 11 apresentavam essa mutação. Caso 2: paciente do sexo masculino, com 4 anos, em avaliação por baixa estatura. Não apresentou alterações laboratoriais, exceto por glicemia elevada (118 mg/dL). Anticorpos anticélulas β foram negativos. Seu pai, uma tia paterna e a avó paterna também apresentavam glicemia discretamente elevada, e a mãe, glicemia normal. A mutação missense em heterozigose, p.Glu221Lys, foi identificada no paciente-índice e em 4 membros da família. Todos os pacientes afetados apresentavam hiperglicemia leve. Essas mutações não foram identificadas nos indivíduos com glicemia normal. O rastreamento de mutações no gene GCK deve ser considerado em pacientes com hiperglicemia crônica leve e de início precoce, história familiar de glicemia elevada e anticorpos anticélulas β negativos. Arq Bras Endocrinol Metab. 2012;56(8):519-24Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) [301477/2009-4]Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Universidade de Sao Paulo (Programa de Apoio aos Novos Docentes)Universidade de Sao Paulo (Programa de Apoio aos Novos Docentes) [2010.1.37155.1.8

Incidental mild hyperglycemia in children: two MODY 2 families identified in Brazilian subjects Hiperglicemia incidental em crianças: duas famílias com MODY 2 identificadas em brasileiros

SUMMARY Maturity-onset diabetes of the young (MODY) is characterized by an autosomal dominant mode of inheritance, early onset of hyperglycemia, and defects of insulin secretion. MODY subtypes described present genetic, metabolic, and clinical differences. MODY 2 is characterized by mild asymptomatic fasting hyperglycemia, and rarely requires pharmacological treatment. Hence, precise diagnosis of MODY is important for determining management and prognosis. We report two heterozygous GCK mutations identified during the investigation of short stature. Case 1: a prepubertal 14-year-old boy was evaluated for constitutional delay of growth and puberty. During follow-up, he showed abnormal fasting glucose (113 mg/dL), increased level of HbA1c (6.6%), and negative β-cell antibodies. His father and two siblings also had slightly elevated blood glucose levels. The mother had normal glycemia. A GCK heterozygous missense mutation, p.Arg191Trp, was identified in the proband. Eighteen family members were screened for this mutation, and 11 had the mutation in heterozygous state. Case 2: a 4-year-old boy investigated for short stature revealed no other laboratorial alterations than elevated glycemia (118 mg/dL); β-cell antibodies were negative. His father, a paternal aunt, and the paternal grandmother also had slightly elevated glycemia, whereas his mother had normal glycemia. A GCK heterozygous missense mutation, p.Glu221Lys, was identified in the index patient and in four family members. All affected patients had mild elevated glycemia. Individuals with normal glycemia did not harbor mutations. GCK mutation screening should be considered in patients with chronic mild early-onset hyperglycemia, family history of impaired glycemia, and negative β-cell antibodies. Arq Bras Endocrinol Metab. 2012;56(8):519-24 SUMÁRIO O diabetes do tipo MODY (maturity-onset diabetes of the young) caracteriza-se por herança autossômica dominante, início precoce da hiperglicemia e defeitos na secreção de insulina. Os subtipos de MODY apresentam diferenças genéticas, metabólicas e clínicas. O MODY 2 é caracterizado por hiperglicemia leve assintomática e raramente requer tratamento farmacológico. O diagnóstico preciso de MODY é importante para se determinar o tratamento e o prognóstico. Relatamos duas mutações no gene GCK em heterozigose identificadas durante investigação de baixa estatura. Caso 1: paciente do sexo masculino, com 14 anos, pré-púbere, avaliado por atraso constitucional do crescimento e da puberdade. Durante o acompanhamento, apresentou glicemia de jejum alterada (113 mg/dL), aumento de HbA1c (6,6%) e anticorpos anticélulas β negativos. Seu pai e dois irmãos também apresentavam glicemia levemente elevada. A mãe tinha glicemia normal. Foi identificada no gene GCK uma mutação missense em heterozigose, p.Arg191Trp. Dezoito membros da família foram rastreados e 11 apresentavam essa mutação. Caso 2: paciente do sexo masculino, com 4 anos, em avaliação por baixa estatura. Não apresentou alterações laboratoriais, exceto por glicemia elevada (118 mg/dL). Anticorpos anticélulas β foram negativos. Seu pai, uma tia paterna e a avó paterna também apresentavam glicemia discretamente elevada, e a mãe, glicemia normal. A mutação missense em heterozigose, p.Glu221Lys, foi identificada no paciente-índice e em 4 membros da família. Todos os pacientes afetados apresentavam hiperglicemia leve. Essas mutações não foram identificadas nos indivíduos com glicemia normal. O rastreamento de mutações no gene GCK deve ser considerado em pacientes com hiperglicemia crônica leve e de início precoce, história familiar de glicemia elevada e anticorpos anticélulas β negativos. Arq Bras Endocrinol Metab. 2012;56(8):519-2

The Interactive Effect of GHR-Exon 3 and -202 A/C IGFBP3 Polymorphisms on rhGH Responsiveness and Treatment Outcomes in Patients with Turner Syndrome

Context: There is great interindividual variability in the response to recombinant human (rh) GH therapy in patients with Turner syndrome (TS). Ascertaining genetic factors can improve the accuracy of growth response predictions. Objective: The objective of the study was to assess the individual and combined influence of GHR-exon 3 and -202 A/C IGFBP3 polymorphisms on the short-and long-term outcomes of rhGH therapy in patients with TS. Design and Patients: GHR-exon 3 and -202 A/C IGFBP3 genotyping (rs2854744) was correlated with height data of 112 patients with TS who remained prepubertal during the first year of rhGH therapy and 65 patients who reached adult height after 5 +/- 2.5 yr of rhGH treatment. Main Outcome Measures: First-year growth velocity and adult height were measured. Results: Patients carrying at least one GHR-d3 or -202 A-IGFBP3 allele presented higher mean first-year growth velocity and achieved taller adult heights than those homozygous for GHR-fl or -202 C-IGFBP3 alleles, respectively. The combined analysis of GHR-exon 3 and -202 A/C IGFBP3 genotypes showed a clear nonadditive epistatic influence on adult height of patients with TS treated with rhGH (GHR-exon 3 alone, R-2 = 0.27; -202 A/C IGFBP3, R-2 = 0.24; the combined genotypes, R-2 = 0.37 at multiple linear regression). Together with clinical factors, these genotypes accounted for 61% of the variability in adult height of patients with TS after rhGH therapy. Conclusion: Homozygosity for the GHR-exon3 full-length allele and/or the -202C-IGFBP3 allele are associated with less favorable short-and long-term growth outcomes after rhGH treatment in patients with TS. (J Clin Endocrinol Metab 97: E671-E677, 2012)Fundacao de Amparo a Pesquisa do Estado de Sao Paulo [05/04726-0, 05/50144-2]Conselho Nacional de Desenvolvimento Cientifico e Tecnologico [301339/2008-9, 300938/06-3, 475870/2009-3, 301477/2009-4

Mutational analysis of TAC3 and TACR3 genes in patients with idiopathic central pubertal disorders

OBJETIVO: Investigar a presença de variantes nos genes TAC3 e TACR3, os quais codificam a NKB e seu receptor (NK3R), respectivamente, em uma coorte de pacientes com distúrbios puberais centrais idiopáticos. \ud SUJEITOS E MÉTODOS: Duzentos e trinta e sete pacientes foram estudados: 114 com puberdade precoce central (PPC), 73 com hipogonadismo hipogonadotrófico isolado normósmico (HHI) e 50 com retardo constitucional do crescimento e desenvolvimento (RCCD). O grupo controle consistiu de 150 indivíduos brasileiros que apresentaram desenvolvimento puberal normal. O DNA genômico foi extraído de sangue periférico, e as regiões codificadoras dos genes TAC3 e TACR3 foram amplificadas e sequenciadas automaticamente. \ud RESULTADOS: Uma variante (p.A63P) foi identificada na NKB, e quatro variantes, p.G18D, p.L58L (c.172C>T), p.W275X e p.A449S, foram identificadas no NK3R, as quais foram ausentes no grupo controle. A variante p.A63P foi identificada em uma menina com PPC, e a variante p.A449S, em uma menina com RCCD. As variantes previamente descritas, p.G18D, p.L58L e p.W275X, foram identificadas em três indivíduos com HHI normósmico do sexo masculino não relacionados. \ud CONCLUSÃO: Variantes raras nos genes TAC3 e TACR3 foram identificadas em pacientes com distúrbios puberais centrais idiopáticos. Mutações de perda de função no gene TACR3 foram associadas com o fenótipo de HHI normósmico. Arq Bras Endocrinol Metab. 2012;56(9):646-52Objective: To investigate the presence of variants in the TAC3 and TACR3 genes, which encode NKB and its receptor (NK3R), respectively, in a large cohort of patients with idiopathic central pubertal disorders. Subjects and methods: Two hundred and thirty seven patients were studied: 114 with central precocious puberty (CPP), 73 with normosmic isolated hypogonadotropic hypogonadism (IHH), and 50 with constitutional delay of growth and puberty (CDGP). The control group consisted of 150 Brazilian individuals with normal pubertal development. Genomic DNA was extracted from peripheral blood and the entire coding region of both TAC3 and TACR3 genes were amplified and automatically sequenced. Results: We identified one variant (p.A63P) in NKB and four variants, p.G18D, p.L58L (c.172C > T), p.W275* and p.A449S in NK3R, which were absent in the control group. The p.A63P variant was identified in a girl with CPP, and p.A449S in a girl with CDGP. The known p.G18D, p.L58L, and p.W275* variants were identified in three unrelated males with normosmic IHH. Conclusion: Rare variants in the TAC3 and TACR3 genes were identified in patients with central pubertal disorders. Loss-of-function variants of TACR3 were associated with the normosmic IHH phenotype. Arq Bras Endocrinol Metab. 2012; 56(9):646-52FAPESPFapesp [05/04726]Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) [302825/2011-8, 305743/2011-8]Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health (NIH)Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health (NIH) [U54 HD28138

FGFR1 and PROKR2 rare variants found in patients with combined pituitary hormone deficiencies

The genetic aetiology of congenital hypopituitarism (CH) is not entirely elucidated. FGFR1 and PROKR2 loss-of-function mutations are classically involved in hypogonadotrophic hypogonadism (HH), however, due to the clinical and genetic overlap of HH and CH; these genes may also be involved in the pathogenesis of CH. Using a candidate gene approach, we screened 156 Brazilian patients with combined pituitary hormone deficiencies (CPHD) for loss-of-function mutations in FGFR1 and PROKR2. We identified three FGFR1 variants (p.Arg448Trp, p.Ser107Leu and p.Pro772Ser) in four unrelated patients (two males) and two PROKR2 variants (p.Arg85Cys and p.Arg248Glu) in two unrelated female patients. Five of the six patients harbouring the variants had a first-degree relative that was an unaffected carrier of it. Results of functional studies indicated that the new FGFR1 variant p.Arg448Trp is a loss-of-function variant, while p.Ser107Leu and p.Pro772Ser present signalling activity similar to the wild-type form. Regarding PROKR2 variants, results from previous functional studies indicated that p.Arg85Cys moderately compromises receptor signalling through both MAPK and Ca2 + pathways while p.Arg248Glu decreases calcium mobilization but has normal MAPK activity. The presence of loss-of-function variants of FGFR1 and PROKR2 in our patients with CPHD is indicative of an adjuvant and/or modifier effect of these rare variants on the phenotype. The presence of the same variants in unaffected relatives implies that they cannot solely cause the phenotype. Other associated genetic and/or environmental modifiers may play a role in the aetiology of this condition

Cytogenetic analysis and detection of KAL-1 gene deletion with fluorescence in situ hybridization (FISH) in patients with Kallmann syndrome

Kallmann syndrome (KS) is a disease clinically characterized by the association of hypogonadotropic hypogonadism and anosmia or hyposmia, for which three modes of transmission have been described: X-linked, autosomal recessive and autosomal dominant. The KAL-1 gene, responsible for the X-linked form of the disease, has been isolated and its intron-exon organization determined. In this study, two families with X-linked KS and four sporadic male patients with hypogonadotropic hypogonadism and anosmia were cytogenetically investigated with high-resolution techniques and FISH. Chromosomal analysis did not reveal any rearrangements or deletions. Deletion of the KAL-1 gene was detected by FISH in only one sporadic patient, with the typical features of KS and a high palate. Among the familial cases renal abnormalities and pes cavus deformity were observed.A síndrome de Kallmann (SK) é caracterizada clinicamente pela associação de hipogonadismo hipogonadotrófico e anosmia ou hiposmia, para a qual três modos de herança foram descritos: ligada ao X, autossômica dominante e recessiva. O gene KAL-1, responsável pela forma da síndrome ligada ao X, foi isolado e sua organização éxon-íntron determinada. Neste estudo, duas famílias com síndrome de Kallmann ligada ao X e quatro indivíduos do sexo masculino com hipogonadismo hipogonadotrófico e anosmia foram citogeneticamente investigados por meio de técnicas de alta-resolução e FISH. A análise citogenética não revelou qualquer rearranjo cromossômico. A deleção do gene KAL-1 foi detectada por FISH em apenas um caso esporádico, em um paciente com sinais característicos de SK e palato alto. Entre os casos familiais foram observadas anomalias renais e pes cavus.552557Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Study of the association between 3111T/C polymorphism of the CLOCK gene and the presence of overweight in schoolchildren,

Objectives: To evaluate the association between 3111T/C polymorphism of the CLOCK gene and the presence of obesity and sleep duration in children aged 6-13 years. In adults, this genetic variant has been associated with duration of sleep, ghrelin levels, weight, and eating habits. Although short sleep duration has been linked to obesity in children, no study has aimed to identify the possible molecular mechanisms of this association to date. Methods: Weight, height, and circumferences were transformed into Z-scores for age and gender. Genotyping was performed using TaqMan methodology. A questionnaire regarding hours of sleep was provided to parents. The appropriate statistical tests were performed. Results: This study evaluated 370 children (45% males, 55% females, mean age 8.5 ± 1.5 years). The prevalence of overweight was 18%. The duration of sleep was, on average, 9.7 hours, and was inversely related to age (p < 0.001). Genotype distribution was: 4% CC, 31% CT, and 65% TT. There was a trend toward higher prevalence of overweight in children who slept less than nine hours (23%) when compared to those who slept more than ten hours (16%, p = 0.06). Genotype was not significantly correlated to any of the assessed outcomes. Conclusions: The CLOCK 3111T/C polymorphism was not significantly associated with overweight or sleep duration in children in this city

A GPR54-activating mutation in a patient with central precocious puberty

Gonadotropin-dependent, or central, precocious puberty is caused by early maturation of the hypothalamic-pituitary-gonadal axis. In girls, this condition is most often idiopathic. Recently, a G protein-coupled receptor, GPR54, and its ligand, kisspeptin, were described as an excitatory neuroregulator system for the secretion of gonadotropin-releasing hormone (GnRH). In this study, we have identified an autosomal dominant GPR54 mutation--the substitution of proline for arginine at codon 386 (Arg386Pro)--in an adopted girl with idiopathic central precocious puberty (whose biologic family was not available for genetic studies). In vitro studies have shown that this mutation leads to prolonged activation of intracellular signaling pathways in response to kisspeptin. The Arg386Pro mutant appears to be associated with central precocious puberty