PubMed HealthSearch

Biomedical subjects

N Freire-Maia

Publications and source records attributed to N Freire-Maia.

At least 19 recordsLinked to original sources

Autosomal recessive cleft lip/palate, ectodermal dysplasia, and minor acral anomalies: report of a Brazilian family.

We report on a Brazilian woman, born to consanguineous (first cousin) parents (F = 1/16) and presenting cleft lip/palate, ectodermal dysplasia, interdigital webbing, and other malformations. Parental consanguinity and possible recurrence in sibs suggest autosomal recessive inheritance. The nosologic aspects with the Martinez syndrome and with the Zlotogora-Ogur syndrome are discussed.

Abnormalities, Multiple

Inbreeding effect on morbidity: IV. Further data in Brazilian populations.

The analysis of the data on 5677 children of 1063 couples from a fourth sample of consanguineous and nonconsanguineous marriages among whites and nonwhites living in the State of Minas Gerais, Brazil led to the following estimates: B (number of abnormal equivalents per gamete) around 0.5; A (morbidity in the non-inbred subsamples) 2-3 percent; B/A 13, 15, and 27 (this suggests that the morbidity disclosed by inbreeding may predominantly represent a mutational load); RR (relative risk) about 2 (this means that among the children of consanguineous marriages there is about double the frequency of abnormalities than in those with nonconsanguineous marriages); AR (attributable risk) for the whole sample about 7% (5% for nonwhites and 15% for whites). These last values show the amount that the frequency of abnormalities would decrease in the population if the risk factor (consanguineous marriages) would be eliminated. AR is higher in whites because the frequency of the risk factor is higher among whites.

Brazil

Hair-nail dysplasia--a new pure autosomal dominant ectodermal dysplasia.

An apparently hitherto undescribed pure ectodermal dysplasia of the tricho-onychic subgroup is described. Its cause is an autosomal dominant gene with complete penetrance and variable expressivity. Differential diagnosis considered 18 conditions belonging to the same subgroup, as well as Clouston syndrome. This report increases the number of conditions of the tricho-onychic subgroup to 19, and the total number of ectodermal dysplasias to 155.

Diagnosis, Differential

Genetic effects in Brazilian populations due to consanguineous marriages.

Estimates of "relative risks" and "attributable risks" are presented for two Brazilian regions with the lowest (F = 0.00030) and the highest (F = 0.00395) inbreeding levels of the country, and for the whole country (F = 0.00088). The abolition of all consanguineous marriages (from second cousins up to and including uncle-niece/aunt-nephew marriages) in Brazil would eliminate only about 0.22, 3.05, and 0.65% of the "total damage," respectively. "Total damage" is defined as including abortions, miscarriages, stillbirths, infant-juvenile mortality (up to the age of 20 years), and anomalies in the survivors. The reduction of prenatal damage would be 0.11, 1.46, and 0.31%, and that of postnatal damage would be 0.49, 6.65, and 1.36%, respectively.

Abortion, Spontaneous

[Consanguinity marriages in Brazil].

This short review deals with the following problems: 1. frequencies of consanguineous marriages in Brazil; 2. their effects on precocious mortality (from abortions up to and including infant-juvenile mortality) and abnormalities among the survivors; 3. genetic counseling for consanguineous marriages; 4. reduction of the prenatal and post-natal damage in consequence of the abolition of the consanguineous marriages in Brazil.

Brazil

Christ-Siemens-Touraine syndrome--a clinical and genetic analysis of a large Brazilian kindred: I. Affected females.

A total of 27 women of a Brazilian kindred are described as having one or more signs of the Christ-Siemens-Touraine syndrome. The history and physical examination were supplemented by four sweat tests and dermatolglyphic analysis. It is suggested that this syndrome has two forms -- a major form (in males) and a minor one (in females). Two signs verified in some of our patients (mosaic patchy distribution of body hair and radial deviation of distal phalanges of index fingers) seem to be here described for the first time. A review of the literature shows a corrected sex ratio between 1 M: 1.21 F and 1 M: 2.38 F among affecteds. Since the manifestation rate of the gene among carriers was estimated at about 0.70, the actual sex ratio is expected to be not lower than 1 M: 1.40 F. Contrary to a general opinion, affected females outnumber affected males.

Adult

Christ-Siemens-Touraine syndrome--a clinical and genetic analysis of a large Brazilian kindred: II. Affected males.

We describe 13 males with Christ-Siemens-Touraine syndrome from one family. History and examination were supplemented by three sweat tests and dermatolglyphic analysis. Some of the patients had two uncommon findings (onychodystrophy and excessive lacrimation), and five had an "incomplete" form of the syndrome. Four signs (distal phalanges of fingers and toes radially and tibially deviated, respectively; facial hypochromic spots; large occipitofrontal circumference) seem to be described for the first time. The segregation proportion in the sibships with at least an affected male was found to be normal (1:1) in 44 series of data (43 from the literature), where a high ascertainment bias was present (155 affected and 68 normal males).

Adolescent

Genetics of acheiropodia ("The handless and footless families of Brazil"): X. Roentgenologic study.

The main radiologic findings from four unrelated cases and two sibs with acheiropodia are presented and discussed. On the basis of such analysis, a clinical and radiologic description of the anomaly is given. The presence of one or more fingers and of a small bone (Bohomoletz bone) in the upper stumps is discussed. These unusual findings in bone structure were assumed to be due to a variability in the expression of the acheiropodia gene. Radiologic studies of some of the acheiropods' normal parents failed to reveal even mild manifestations of the gene in the heterozygous state. No recognizable pattern was found in the dermal ridges on the end of the acheiropods' upper or lower stumps.

Abnormalities, Multiple

Genetic investigations in a Northern Brazilian island. II. Random drift.

18 albinos were born on Lençóis island. Since 3 of them died and 5 emigrated, the prevalence of albinism is about 3% in the island. 2 inbred brothers with brachydactyly of the index fingers and 1 case of 'achondroplasia' were also found. The analysis of the population structure of the island suggests that its high frequency of albinism may have been produced by random drift. The index of isolation of its present population is roughly 17--27. Genealogical, clinical and histological data are presented and anslyzed. Natural selection is not acting against the albinism gene at a measurable rate. Cytogenetic investigations among albinos and normals did not reveal any difference as regards frequency of aneuploidy, association of acrocentrics and chromatid gaps. The role of random processes in evolution is mentioned and the possibility that they may be more important than it is sometimes assumed is stressed.

Achondroplasia