Current status of prenatal diagnosis in Cuba: causes of low prevalence of Down syndrome.

OBJECTIVES: To analyze trends in cytogenetic prenatal diagnosis in Cuba and to analyze possible causes leading to a low Down syndrome prevalence in a country where the triple test is not available. METHODS: An analysis of the Cuban program in prenatal cytogenetic diagnosis from 1984 to 2012 was conducted. Results are described, with particular emphasis on indications, abnormal results, types of invasive procedures, and terminations of pregnancy. RESULTS: Cytogenetic prenatal diagnostic analyses (n = 75,095) were conducted; maternal age was the indication for 77.9% of the amniocenteses and chorionic villus samplings. The detection rate of chromosomally abnormal pregnancies was 2.3% for maternal age and increased to 8-9% for other indications. When a chromosomal abnormality was identified, 88.5% terminated the pregnancy. In 2002, the live birth prevalence of Down syndrome was 8.4 per 10,000 live births, and in 2012, 7 per 10,000. CONCLUSION: Prenatal diagnosis in Cuba has contributed to a significant reduction in chromosomal aberrations. The impact increased because of the demographic trends of the population, the high index of terminations of pregnancy, and the establishment of a network of cytogenetic laboratories throughout Cuba.

[Screening for congenital hypothyroidism, phenylketonuria, galactosemia and biotinidase deficiency in a sample of mentally retarded patients in the city of Havana]. / Cribado de hipotiroidismo congénito, fenilcetonuria, galactosemia y deficiencia de biotinidasa en una muestra de retrasados mentales de Ciudad de La Habana.

INTRODUCTION: Congenital hypothyroidism (CH), phenylketonuria (PKU), galactosemia (GAL) and biotinidase deficiency (BD) are innate errors in metabolism that share varying degrees of mental retardation (MR) as a common characteristic. AIMS. The aim of our study was to screen individuals with MR of unknown origin for CH, PKU, GAL and BD. PATIENTS AND METHODS: Venous blood samples were collected on SS 903 specimen collection paper from 55 individuals with MR of unspecific origin born within the period 1977 1997. CH diagnosis was performed through determination of total thyroxine (T4) and thyroid stimulating hormone (TSH), using the UMELISA T4 and neonatal TSH reagent kits, respectively, and the detection of PKU, GAL and BD was conducted by determining phenylalanine (Phe), total galactose (Gal) and biotinidase enzyme activity (Biot) using UMTEST PKU, GAL and BIOTINIDASA. RESULTS: The mean values obtained for the analytes that were evaluated were: 0.8 mUI of TSH/L of total blood (EEM: 0.2), 113.1 nmol of T4/L of serum (EEM: 5.4), 67.7 mol of Phe/L of total blood (EEM: 0.1), 0.1 mmol of Gal/L of total blood (EEM: 0.01), and Biot activity was normal in all cases. CONCLUSIONS: This study enabled us to determine the T4, TSH, Phe and Gal levels in a sample from the Cuban population with MR of unknown causation. In addition, slightly higher levels of T4 were found in children who had hyperkinesis

Cribado de hipotiroidismo congénito, fenilcetonuria, galactosemia y deficiencia de biotinidasa en una muestra de retrasados mentales de Ciudad de La Habana / Screening for congenital hypothyroidism, phenylketonuria, galactosemia and biotinidase deficiency in a sample of mentaly retarded patients in the city of Havana

Introducción.El hipotiroidismo congénito (HC), la fenilcetonuria (FCU), la galactosemia (GAL) y la deficiencia de biotinidasa (DB) son errores innatos del metabolismo que tienen como característica común el retraso mental (RM) de diferentes gradaciones. Objetivo. Realizar el cribado de HC, FCU, GAL y DB en individuos con RM de etiología desconocida. Pacientes y métodos. Se recolectaron muestras de sangre venosa en tarjetas de papel de filtro S&S 903 de 55 individuos con RM sin etiología específica, nacidos en el período de 1977-1997. El diagnóstico de HC se realizó mediante las determinaciones de tiroxina total (T4) y hormona estimulante del tiroides (TSH), con los estuches de reactivos UMELISA T4 y TSH neonatal, respectivamente, y la detección de FCU, GAL y DB mediante las determinaciones de fenilalanina (Phe), galactosa total (Gal) y la actividad de la enzima biotinidasa (Biot), con los UMTEST PKU, GAL y BIOTINIDASA. Resultados. Los valores medios obtenidos para los análitos evaluados fueron: 0,8 mUI de TSH/L de sangre total (EEM: ñ0,2), 113,1 nmol de T4/L de suero (EEM: ñ5,4), 67,7 µmol de Phe/L de sangre total (EEM: ñ0,1), 0,1 mmol de Gal/L de sangre total (EEM:ñ0,01) y la actividad de Biot fue normal en todos los casos. Conclusiones. Este estudio permitió conocer los niveles de T4, TSH, Phe y Gal en una muestra de población cubana con RM de etiología desconocida. Además, se encontraron niveles ligeramente elevados de T4 en niños que tenían hipercinesia (AU)