RESUMO
OBJECTIVE: To determine if the racial/ethnic inequity in growth hormone (GH) use is due to differences in GH stimulation testing and/or prescribing patterns in children referred for endocrine evaluation of short stature. STUDY DESIGN: Retrospective chart review was performed including children aged 2-16 years, height z-score of ≤-1.5, and of non-Hispanic White (NHW), non-Hispanic Black (NHB), or Hispanic race/ethnicity, referred for endocrine growth evaluation between January 2012 and December 2019. RESULTS: This study included 7425 children (5905 NHW, 800 NHB, and 720 Hispanic). GH stimulation testing was performed in 992, and 576 were prescribed GH. NHW children were 1.4 (95% CI, 1.04-1.8) times more likely than NHB children and 1.7 (95% CI, 1.2-2.2) times more likely than Hispanic children to undergo GH stimulation testing. GH-treated NHB children had (1) a lower median peak GH concentration when compared with NHW (P = .02) and Hispanic (P = .08) children (NHB 4.7 ng/mL [95% CI, 1.2-8.3 ng/mL] ng/mL, NHW 7.2 ng/mL [95% CI, 4.9-9.7 ng/mL], Hispanic 7.1 ng/mL [95% CI, 4.3-11.9 ng/mL]); (2) lower median height z-scores than NHW (P = .01) but not Hispanic children (P = .5); and (3) a greater height deficit from midparental height when compared with NHW (P = .01) and Hispanic (P = .002) children. CONCLUSIONS: Racial and ethnic disparities exist in the evaluation and treatment of children with disordered growth. This likely results from both overinvestigation of NHW children as well as underinvestigation and undertreatment of children from minority communities. The evaluation and treatment of children with short stature should be determined by clinical concern alone, but this is not current practice.
Assuntos
Negro ou Afro-Americano , Transtornos do Crescimento/diagnóstico , Disparidades em Assistência à Saúde/etnologia , Hispânico ou Latino , Hormônio do Crescimento Humano/deficiência , População Branca , Adolescente , Estatura , Criança , Pré-Escolar , Técnicas de Diagnóstico Endócrino , Feminino , Transtornos do Crescimento/etnologia , Transtornos do Crescimento/terapia , Humanos , Masculino , Padrões de Prática Médica , Estudos RetrospectivosRESUMO
On average, Peruvian individuals are among the shortest in the world1. Here we show that Native American ancestry is associated with reduced height in an ethnically diverse group of Peruvian individuals, and identify a population-specific, missense variant in the FBN1 gene (E1297G) that is significantly associated with lower height. Each copy of the minor allele (frequency of 4.7%) reduces height by 2.2 cm (4.4 cm in homozygous individuals). To our knowledge, this is the largest effect size known for a common height-associated variant. FBN1 encodes the extracellular matrix protein fibrillin 1, which is a major structural component of microfibrils. We observed less densely packed fibrillin-1-rich microfibrils with irregular edges in the skin of individuals who were homozygous for G1297 compared with individuals who were homozygous for E1297. Moreover, we show that the E1297G locus is under positive selection in non-African populations, and that the E1297 variant shows subtle evidence of positive selection specifically within the Peruvian population. This variant is also significantly more frequent in coastal Peruvian populations than in populations from the Andes or the Amazon, which suggests that short stature might be the result of adaptation to factors that are associated with the coastal environment in Peru.
Assuntos
Estatura/genética , Fibrilina-1/genética , Mutação de Sentido Incorreto , Seleção Genética , Feminino , Frequência do Gene , Estudo de Associação Genômica Ampla , Hereditariedade , Humanos , Indígenas Sul-Americanos/genética , Masculino , Microfibrilas/química , Microfibrilas/genética , PeruRESUMO
We present the case of a 19-year-old man with a growth disorder, which was undefined, despite extensive evaluation. Whole exome sequencing demonstrated a novel homozygous frameshift mutation in CUL7, one of the causative genes of 3-M syndrome. We discuss the utility of exome sequencing in diagnosing rare disorders.
Assuntos
Proteínas Culina/genética , Nanismo/genética , Exoma/genética , Mutação da Fase de Leitura , Transtornos do Crescimento/genética , Hipotonia Muscular/genética , Análise de Sequência de DNA , Nanismo/diagnóstico , Humanos , Masculino , Hipotonia Muscular/diagnóstico , Fenótipo , Coluna Vertebral/anormalidades , Adulto JovemRESUMO
AIM: To investigate LIN28B gene variants in children with idiopathic central precocious puberty (CPP). PATIENTS AND METHODS: We studied 178 Brazilian children with CPP (171 girls, 16.8% familial cases). A large multiethnic group (1,599 subjects; Multiethnic Cohort, MEC) was used as control. DNA analysis and biochemical in vitro studies were performed. RESULTS: A heterozygous LIN28B variant, p.H199R, was identified in a girl who developed CPP at 5.2 years. This variant was absent in 310 Brazilian control individuals, but it was found in the same allele frequency in women from the MEC cohort, independent of the age of menarche. Functional studies revealed that when ectopically expressed in cells, the mutant protein was capable of binding pre-let-7 microRNA and inhibiting let-7 expression to the same extent as wild-type Lin28B protein. Other rare LIN28B variants (p.P173P, c.198+ 32_33delCT, g.9575731A>C and c.-11C>T) were identified in CPP patients and controls. Therefore, no functional mutation was identified. CONCLUSION: In vitro studies revealed that the rare LIN28B p.H199R variant identified in a girl with CPP does not affect the Lin28B function in the regulation of let-7 expression. Although LIN28B SNPs were associated with normal pubertal timing, rare variations in this gene do not seem to be commonly involved in the molecular pathogenesis of CPP.
Assuntos
Proteínas de Ligação a DNA/genética , Mutação de Sentido Incorreto , Puberdade Precoce/genética , Adolescente , Adulto , Substituição de Aminoácidos , Criança , Pré-Escolar , Estudos de Coortes , Proteínas de Ligação a DNA/biossíntese , Feminino , Regulação da Expressão Gênica/genética , Células HEK293 , Células HeLa , Humanos , Lactente , Recém-Nascido , Masculino , MicroRNAs/biossíntese , MicroRNAs/genética , Puberdade Precoce/metabolismo , Proteínas de Ligação a RNARESUMO
Genome-wide association (GWA) studies have identified common variants that are associated with a variety of traits and diseases, but most studies have been performed in European-derived populations. Here, we describe the first genome-wide analyses of imputed genotype and copy number variants (CNVs) for anthropometric measures in African-derived populations: 1188 Nigerians from Igbo-Ora and Ibadan, Nigeria, and 743 African-Americans from Maywood, IL. To improve the reach of our study, we used imputation to estimate genotypes at approximately 2.1 million single-nucleotide polymorphisms (SNPs) and also tested CNVs for association. No SNPs or common CNVs reached a genome-wide significance level for association with height or body mass index (BMI), and the best signals from a meta-analysis of the two cohorts did not replicate in approximately 3700 African-Americans and Jamaicans. However, several loci previously confirmed in European populations showed evidence of replication in our GWA panel of African-derived populations, including variants near IHH and DLEU7 for height and MC4R for BMI. Analysis of global burden of rare CNVs suggested that lean individuals possess greater total burden of CNVs, but this finding was not supported in an independent European population. Our results suggest that there are not multiple loci with strong effects on anthropometric traits in African-derived populations and that sample sizes comparable to those needed in European GWA studies will be required to identify replicable associations. Meta-analysis of this data set with additional studies in African-ancestry populations will be helpful to improve power to detect novel associations.