Reduced levels of uridine diphosphate glucose pyrophosphorylase activity in fetal and neonatal human and guinea pig liver.

Uridine diphosphate glucose pyrophosphorylase (UDPGPP) is the first enzyme in the bilirubin conjugation pathway. A study aiming to screen for red blood cell UDPGPP deficiency in newborns with hyperbilirubinemia was carried out. No individuals with severe UDPGPP deficiency were found, however, levels of UDPGPP in premature and at term newborns were lower than in adults. These findings led to the study of UDPGPP in human fetal, neonatal and adult liver, using guinea pig tissues as a parallel control. UDPGPP activities in fetal and neonatal samples were also significantly lower than in adult ones in both species. Therefore, it is postulated that the reduced levels of UDPGPP in fetal and neonatal liver could be a factor which contributes to the pathogenesis of the physiologic jaundice in human newborns.

De novo del(4) (p15.32) with incomplete expression of the Wolf-Hirschhorn syndrome.

A 7 7/12-year-old girl with a de novo deletion 4p15.32----pter without the typical Wolf-Hirschhorn syndrome (WHS) is presented. This observation and others from medical literature suggest that monosomy 4p15.31----4p15.32, rather than 4p16, is the cause of the typical WHS.

Familial inv(2) (p2300q11.2).

A hitherto undescribed inv(2) (p2300q11.2) was found in 2 generations of a family ascertained through a holoprosencephalic liveborn boy with normal karyotype. This inversion, quite probably not related to the child malformations, does not seem neither impair reproductive fitness nor to yield viable recombination aneusomies.

Identificación de dos genes distintos de Talasemia ß en una familia mexicana / Identification of 2 distinct genes of beta thalassemia in a Mexican family

Una mujer de 21 años de edad con antecedentes de 11 años de anemia hemolítica fue diagnosticada como heterocigota compuesta para 2 genes diferentes de talasemia ß: ß- y ß+. La madre ß-/ß con Hb A2 elevada y el padre ß+/ß con Hb A2 normal mostraron elevación en la relación de cadenas globínicas alfa/no-alfa (1.39 y 1.34, respectivamente), lo que confirmó una deficiencia de síntesis de cadenas ß. 2 hermanas con el mismo genotipo ß-/ß+, presentaron también anemia hemolítica, otras 2 fueron heterocigotas simples ß+/ß y 3 más homocigotos normales. Este estudio demuestra por primera vez la presencia del gene ß+ con Hb A2 normal en población mexicana

Hemoglobina Riyadh beta 120 (GH3) LIS-ASN en tres familias mexicanas. / Hemoglobin Riyadh beta 120 (GH3) LIS leads to ASN in 3 Mexican families

Durante el estudio de hemoglobinas anormales en el noroccidente de Mexico se encontraron 3 individuos sin parentesco aparente, portadores de Hb Riyadh. Los estudios hematologicos de siete portadores de las tres familias de los casos indices no mostraron alteracion de siete portadores de las tres familias de los casos indices no mostraron alteracion, lo que confirma la inocuidad de esta Hb anormal. Aunque el hallazgo de esta mutante en individuos mexicanos pudiera ser debido a migracion, la hipotesis de una mayor susceptibilidad de mutacion en algunas regiones especificas del ADN del gene globinico beta parece mas factible

Abnormal hemoglobins in Northwestern Mexico.

Blood samples from 9,929 individuals in Northwestern Mexico were assayed for abnormal hemoglobins (Hbs). alpha-thal, beta-thal, beta s and beta c traits, as well as rare abnormal Hbs were observed with variable low frequencies (0 to 0.45%). Eight out of eleven rare abnormal Hbs detected so far have been characterized: Three Hb Riyadh, one Hb J Georgia, one Hb Fannin-Lubbock, one Hb Chiapas and two Hb Tarrant. These results suggest that abnormal Hbs do not constitute a regional public health problem and reflect a wide ethnologic heterogeneity.