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Biomedical subjects

J Nazer

Publications and source records attributed to J Nazer.

At least 37 records · Page 2Linked to original sources
PubMed1996

[Polydactyly: a genetic epidemiological study in Santiago, Chile].

The aim of this work was to study the prevalence at birth and family aggregation of polydactyly in Chile. We studied 125,652 newborns between 1969 and 1991. The prevalence was 1,329 for each 1,000 live newborns and higher in males than in females. Familial recurrence was 22.5% and gene penetrance was estimated as 0.5 for the postaxial-A type and 0.3 for the postaxial-B type. Gene penetrance for postaxial-B type was higher in males. Estimation of gene frequencies and mutation rates gave the highest values for postaxial-B polydactyly.

Chile↗
PubMed1994

[Duffy blood group in malformed newborns and their mothers].

The aim of this work is to analyze the distribution of Duffy blood group and the reproductive history of 148 malformed newborns and their mothers compared to 131 control pairs. The mother-child segregation of the system is analyzed using ITO matrixes. A higher frequency of heterozygote mothers for the system was found among the malformed group compared to controls. No differences in the reproductive history was found between Duffy system homozygote or heterozygote mothers.

Case-Control Studies↗
PubMed1994

[Prevention of neutral tube closure defects, apropos of a case of iniencephaly].

We present a newborn with a malformation in the central nervous system that isn't frequent, the ininencephaly: this consist in the absence of the squamous part of the occipital bone, exaggerated cervical-thoracic retroflexion, high raquischisis, and with other malformations. Died at half hour, by global insufficiency respiratory due lug hypoplasia, verify by necropsies. In the Clinic Hospital of the University of Chile the incidence is 1 in 40,000 life newborn. We review the prevent of the nerval tube defect with the use of folic acid in the diet of the future woman who is going to became pregnant.

Abnormalities, Multiple↗
PubMed1994

[Maternal age as a risk factor for congenital malformations].

We studied 131,899 consecutive births at the Maternity of the University of Chile Clinical Hospital, finding 4887 newborns with congenital malformations (representing a rate of 37.05 per 1000 alive newborns). Between January 1982 and December 1992 there were 41,344 births and 295 stillbirths (0.7%). Among the latter, 41 were malformed (13.9%). A graphic comparing the mean annual rates of malformations and maternal ages, shows a sustained increase in malformations form 1972 to 1988, that decreases thereafter and stabilizes since 1982. There is a marked parallelism between the curves of malformation rates and maternal age (t21 = 1.057, p < 0.1). It is concluded that the risk of congenital malformations increases along with maternal ages.

Adult↗
PubMed1993

[MN blood group and congenital malformations].

This work analyzes the mother-son segregation of MN blood group in malformed and normal newborns. MN blood group was measured in 90 malformed, 70 paired normal newborns and their respective mothers, at the Maternity of the University of Chile Clinical Hospital. The expected values for the different mother-child pairs were calculated according to the ITO matrix method, using maximally probable appraisers. Among malformed newborns, there was an excess of heterozygous sons when the mother was homozygous for the MN system. Among malformed males, there was an excess of MM-MN and MN-MM mother-son pairs. Among control newborns, no distortions were found. These results suggest that there is a strong association between MN heterozygosis, sex and congenital malformations.

Congenital Abnormalities↗
PubMed1992

[Epidemiologic study of factors associated with hypospadias].

From August 60 to December 90, 103 male newborns with hypospadias were diagnosed among 124 588 consecutive newborns examined (8.3 per 10,000). Mortality among them was 1.94%. The annual incidence rate increased significantly over the study period (p < 0.001. Hypospadias was an isolated finding in 92% of cases, and its was associated to other non genital malformation in 8.7%. Location of hypospadias was distal in 73% and proximal in 15.5%. There was no seasonal variation in the incidence rate. Weight of affected individuals did not differ from that of controls. Older age of parents among affected individuals was not statistically significant.

Abnormalities, Multiple↗
PubMed1991

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.

ABO Blood-Group System↗
PubMed1991

[Increase of incidence of Down syndrome and its possible relation with increased maternal age].

Among 47,458 consecutive births taking place between july 1977 and december 1989, we found 83 newborns with Down syndrome, for a 1.74/1000 live births incidence rate. This compares to a rate of 1.39 rate observed at the same maternity from 1971 to 1977 (NS). The mean age of all mothers was 25.9 years as compared to 31.87 for mothers of children with Down syndrome (p < 0.00001). The mean maternal age has increased from 24.34 in 1977 to 27.38 in 1988 (p < 0.0001), mostly due to a greater proportion of the 25 to 29 year-old group of mothers. These data support, although not conclusively, that the increased incidence of Down syndrome in our population is related to older maternal age.

Adolescent↗
PubMed1990

[Incidence of malformations of the central nervous system: 1978-1988].

During the period Jan 1978 to Dec 1988, 41,867 deliveries took place at the University of Chile Hospital. Among them, 148 babies were found to have malformations of the central nervous system, an incidence of 3.6 per 1000 live births. A longitudinal study from 1969 to 1988 suggests a yearly increment of 0.1% in the incidence rate of these malformations. The comparison of some quantitative variables, such as gestational age, birthweight, number of previous abortions and some risk factors like maternal illness, bleeding, radiation exposure, drug ingestion during the first trimester of pregnancy and instructional level of both parents show significant differences between the malformed and the control newborns. No significant differences were found for maternal age, sex nor seasonal variation.

Abnormalities, Drug-Induced↗
PubMed1989

[Incidence of congenital malformations in Chile from 1969 to 1986. Results of a Latin-American collaborative study].

At present, congenital malformations contribute more to infant mortality, given the significant decrease in overall infant mortality rate observed in Chile. A significant and steady increase in the prevalence of congenital malformations was demonstrated at the Clinical Hospital, University of Chile, from 1969 to 1986. Better epidemiologic surveillance is needed to accurately estimate the magnitude of this problem and give orientation for preventive measures.

Chile↗
PubMed1989

[Congenital malformations: a model predictive based on risk factors].

Several risk factors were studied in regard to congenital malformations. Malformed newborns (n = 1200) and controls (n = 1200) seen at the Universidad de Chile Hospital between 1969 and 1979 were examined. Their mothers were asked about possible risk factors. Parenteral age and birth order was significantly higher for malformed newborns than for controls. A family history of congenital malformations was more frequent in malformed newborns. Infertility, metrorrhagia and maternal diseases during pregnancy were more frequent in malformed newborns than in controls. A function that discriminates between controls mothers and mothers of malformed newborns was obtained by a logistic regression model. This function correctly predicted 65% of cases.

Congenital Abnormalities↗