Frequency of low carnitine levels in children on dialysis.

To determine the frequency of low carnitine levels, we measured serum carnitine in pediatric patients on peritoneal dialysis (PD) and hemodialysis (HD). Our prospective cross-sectional study was conducted from September 2004 to March 2005 in a single pediatric center, and included patients under 17 years of age who had been on HD or PD for more than 3 months. Patients with primary carnitine deficiency were excluded. A 4-day food diary was used for carnitine intake quantification. Serum total and free carnitine and acylcarnitine were measured. We compared patients with low and normal carnitine levels using the chi-square test, Mann-Whitney U-test, and Spearman correlation. Of 100 study patients, 70 were on PD, and 61 were male. The median age was 13 years, and the median time on dialysis, 10.5 months. Median serum free carnitine was 32.75 nmol/mL. Carnitine levels were lower than normal in 75 patients and reached the level of deficiency in 29. No difference was found between the dialysis modality types for any fraction of carnitine. No correlation was found between the level of free carnitine and time on dialysis (r = -0.009, p = 0.9) or carnitine intake (r = -0.84, p = 0.4). In conclusion, the frequency ofl ow serum carnitine among pediatric patient on dialysis is high.

[Epidemiology of congenital hypothyroidism in Mexico]. / Epidemiología del hipotiroidismo congénito en México.

OBJECTIVE: To describe the epidemiological characteristics of congenital hypothyroidism (CH) in newborns (NB) detected by the Ministry of Health of Mexico (SSA). MATERIAL AND METHODS: A cross-sectional study was conducted. Thyroid stimulating hormone (TSH) was quantified in 1,379,717 blood samples of NB (from umbilical cord or heel prick), collected in Guthrie cards, between January 2001 and December 2002, in medical units of the SSA. The samples with TSH > or = 15 microUI/ml for cord blood and > or = 10 microUI/ml for heel blood were considered suspicious and were submitted for confirmation by thyroid hormone profile and/or scintigraphy. When the results were positive, the case was registered as confirmed CH and the clinical and demographic data were recorded in specific formats. Statistical analysis was performed using descriptive statistics. RESULTS: The prevalence of CH was 4.12 x 10,000 NB, with female predominance (66.84%). Regional variations in the prevalence were observed, the highest in Quintana Roo (8.13 x 10,000 NB) and the lowest in Sinaloa (0.62 x 10,000 NB). Abnormalities included 57.46% of ectopic glands, 35.91% of athyrosis, and 6.63% abnormal thyroid function conditions. The main clinical features were umbilical hernia (43.73%) and jaundice (41.58%). A total of 151 (17.12%) suspicious NB were not confirmed because of incomplete or inaccurate identification data, death of the NB, parent refusal, and change of address. CONCLUSIONS: CH was present in 1:2,426 NB, with a female predominance (2:1); an ectopic thyroid was the most common finding, and its prominent clinical features were umbilical hernia and jaundice.

Epidemiología del hipotiroidismo congénito en México / Epidemiology of congenital hypothyroidism in Mexico

OBJETIVO: Describir las características epidemiológicas del hipotiroidismo congénito en recién nacidos en unidades médicas de la Secretaría de Salud de México. MATERIAL Y MÉTODOS: Estudio transversal en el cual se cuantificó tirotropina en 1 379 717 muestras de sangre de recién nacidos (de cordón umbilical o de talón), recolectadas en papel filtro, de enero de 2001 a diciembre de 2002, en unidades médicas de la Secretaría de Salud. Las muestras con tirotropina >15 æUI/ml para sangre de cordón, y > 10 æUI/ml para talón, se consideraron sospechosas, y se notificaron para realizar el perfil tiroideo y gammagrafía. Cuando los resultados fueron positivos, el caso se registró como hipotiroidismo congénito confirmado, y se anotaron los datos clínicos y demográficos en formatos específicos. Se utilizó estadística descriptiva estándar. RESULTADOS: Se encontró una prevalencia de 4.12 x 10 000 recién nacidos, con predominancia del sexo femenino (66.84 por ciento). Se observaron variaciones estatales en la prevalencia, máxima en Quintana Roo (8.13 x 10 000 recién nacidos) y mínima en Sinaloa (0.62 X 10 000). Se encontraron 57.46 por ciento tiroides ectópicas, 35.91 por ciento agenesias tiroideas y 6.63 por ciento defectos de la función de las hormonas tiroideas. Los principales datos clínicos fueron hernia umbilical (43.73 por ciento) e ictericia (41.58 por ciento). A 151 (17.12 por ciento) sospechosos no se les realizó estudio confirmatorio debido a datos incompletos o falsos en la ficha de identificación, fallecimiento del recién nacido, renuencia de los padres y cambio de domicilio. CONCLUSIONES: El hipotiroidismo se presentó en 1:2 426 recién nacidos, con predominio femenino (2:1), siendo la ectopia tiroidea su forma más común, y la hernia umbilical y la ictericia sus datos clínicos prominentes.

Galactosemia como causa de colestasis neonatal prolongada / Prolonged neonatal cholestasis due to galactosemia: a report of four cases

Se presentan cuatro casos de galactosemia clásica cuya manifestación clínica inicial fue colestasis neonatal prolongada, atendidos en el Servicio de Gastroenterología del Instituto Nacional de Pediatría de la Ciudad de México, durante el período comprendido de 1987 a 1990. El diagnóstico definitivo se hizo mediante la medición de la actividad de la enzima galactosa 1-fosfato uridil transferasa en eritrocitos (prueba de Beutler). El manejo de los pacientes consistió básicamente en la restricción de galactosa en la dieta. Dos de los pacientes tuvieron una evolución clínica desfavorable, presentamos uno de ellos secuelas neurológicas importantes y el otro paciente falleció (septicemia)