Nazer J

Identification of novel mutations in SHH and ZIC2 in a South American (ECLAMC) population with holoprosencephaly

Abstract. Holoprosencephaly (HPE) is genetically heterogeneous with four genes, SIX3, SHH, TGIF, and ZIC2 that have been identified to date and that are altered in 12% of patients. To analyze this prevalence in a South American population-based sample (57 HPE cases in 244,511 live and still births or 1 in 4300), we performed a mutational study of these genes in 30 unrelated children (26 newborns and 4 non-newborns) with HPE being ascertained by ECLAMC (Latin American Collaborative Study of Congenital Malformations). We identified three novel mutations: two were missense mutations of the SHH gene (Cys183→Phe; His140→Pro); the third mutation was a 2-bp deletion in the zinc-finger region of the ZIC2 gene. These molecular results explained 8% (2/26 newborn samples) of the HPE cases in this South American population-based sample, a proportion similar to our previously published data from a collection of cases.

Quiste ovárico fetal: diagnóstico ecográfico prenatal. Evolución y tratamiento postnatal. Casos clínicos

Ovarian cysts are found in 32% of necropsies performed to neonates. They can also be diagnosed during gestation by ultrasonography. The clinical evolution of these cysts is variable, but in most cases the prognosis is favorable. Some complications such as ovarian torsion, bleeding, rupture and peritonitis have been described. We report two newborn girls with ovarian cysts, diagnosed during gestation. One required an emergency operation due to vomiting and abdominal distension, interpreted as a possible torsion of the cyst. The second girl was operated at the fourth day of life, finding a left ovarian cyst with torsion of the pedicle. Both girls had a favorable postoperative evolution (Rev Med Chile 2003; 131: 665-668)

Segregation Distortions of the ABO and Rh Systems in Malformed Newborns

This study compares the segregation of the ABO and Rh systems between malformed newborns and a control group with two purposes: (1) to evaluate the participation of genetic factors associated with these blood groups in the production of congenital malformations, and (2) to prove, indirectly, the existence of reproductive losses associated with congenital malformations. The newborns and their mothers were typed for ABO and Rh groups. Gene frequencies were similar in malformed and control newborns. In the female malformed newborns, an excess of O-B pairs and a deficit of B-B pairs in the ABO system, and an excess of Rh(-)-Rh- pairs in the Rh system were found.

Uniparental ancestry markers in Chilean populations

Abstract The presence of Native Americans, Europeans, and Africans has led to the development of a multi-ethnic, admixed population in Chile. This study aimed to contribute to the characterization of the uniparental genetic structure of three Chilean regions. Newborns from seven hospitals in Independencia, Providencia, Santiago, Curicó, Cauquenes, Valdívia, and Puerto Montt communes, belonging to the Chilean regions of Santiago, Maule, and Los Lagos, were studied. The presence of Native American mitochondrial DNA (mtDNA) haplogroups and two markers present in the non-recombinant region of the Y chromosome, DYS199 and DYS287, indicative of Native American and African ancestry, respectively, was determined. A high Native American matrilineal contribution and a low Native American and African patrilineal contributions were found in all three studied regions. As previously found in Chilean admixed populations, the Native American matrilineal contribution was lower in Santiago than in the other studied regions. However, there was an unexpectedly higher contribution of Native American ancestry in one of the studied communes in Santiago, probably due to the high rate of immigration from other regions of the country. The population genetic sub-structure we detected in Santiago using few uniparental markers requires further confirmation, owing to possible stratification for autosomal and X-chromosome markers.

Factores de riesgo de ocurrencia y gravedad de malformaciones congénitas

Background The relative importance of congenital malformations as a cause of death in the first year of life is increasing along with the control of preventable causes of perinatal mortality. Aim To identify risk factors for congenital malformations. Patients and methods Retrospective case-control study of births registered in the database of The Latin American Collaborative Study of Congenital Malformations (ECLAMC), in the period 2001-2010. Results Birth weight and gestational age were significantly lower in cases than controls, behaving as risk factors and associated with a greater severity of congenital malformations. The risk and severity of congenital malformations increased along with mothers age. Fetal growth retardation, a history of congenital malformations in the family, physical factors and acute illnesses of the mother in the first trimester of pregnancy were also significant risk factors for congenital malformations and their severity. The educational level of the mother was a protective factor for congenital malformations and their severity. Conclusions Variables previously identified as risk factors for congenital malformations, were significantly related with the occurrence of congenital malformations and their severity.BACKGROUND The relative importance of congenital malformations as a cause of death in the first year of life is increasing along with the control of preventable causes of perinatal mortality. AIM To identify risk factors for congenital malformations. PATIENTS AND METHODS Retrospective case-control study of births registered in the database of The Latin American Collaborative Study of Congenital Malformations (ECLAMC), in the period 2001-2010. RESULTS Birth weight and gestational age were significantly lower in cases than controls, behaving as risk factors and associated with a greater severity of congenital malformations. The risk and severity of congenital malformations increased along with mothers age. Fetal growth retardation, a history of congenital malformations in the family, physical factors and acute illnesses of the mother in the first trimester of pregnancy were also significant risk factors for congenital malformations and their severity. The educational level of the mother was a protective factor for congenital malformations and their severity. CONCLUSIONS Variables previously identified as risk factors for congenital malformations, were significantly related with the occurrence of congenital malformations and their severity.Background: The relative importance of congenital malformations as a cause of death in the first year of life is increasing along with the control of preventable causes of perinatal mortality. Aim: To identify risk factors for congenital malformations. Patients and methods: Retrospective case-control study of births registered in the database of The Latin American Collaborative Study of Congenital Malformations (ECLAMC), in the period 2001 - 2010. Results: Birth weight and gestational age were significantly lower in cases than controls, behaving as risk factors and associated with a greater severity of congenital malformations. The risk and severity of congenital malformations increased along with mother’s age. Fetal growth retardation, a history of congenital malformations in the family, physical factors and acute illnesses of the mother in the first trimester of pregnancy were also significant risk factors for congenital malformations and their severity. The educational level of the mother was a protective factor for congenital malformations and their severity. Conclusions: Variables previously identified as risk factors for congenital malformations, were significantly related with the occurrence of congenital malformations and their severity.