N. Freire-Maia

Ectodermal Dysplasias Revisited

This paper presents a historical view of the development of the concept of ectodermal dysplasia, analyses five current “definitions” of the group, and classifies 52-57 ectodermal dysplasias into subgroups on the basis of criteria developed by the Author.

A previously undescribed condition: tricho‐odonto‐onycho‐dermal syndrome. A review of the tricho‐odonto‐onychial subgroup of ectodermal dysplasias

An apparently hitherto undescribed ectodermal dysplasia/malformation syndrome is presented. The patient, the last son in an outbred sibship of four males, presents scalp hypotrichosis, aplasia cutis congenita of the scalp, dental abnormalities, onychodysplasia, dry skin with hypochromic and atrophic (poikiloderma‐like) spots with vicarious (marginal) hyperchromia, unusual facies, asymmetrical skull, absent right nipple, irregular areolae, palmar keratosis, dermatoglyphic alterations, syndactyly, clinodactyly, phalangeal aplasias and hypoplasias, right leukoma, abnormal EEG, and other findings. The aetiology is unknown. A review of seventeen ectodermal dysplasias is presented for differential diagnosis.

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 dyspiasias to 155.

X‐linked hypohidrotic ectodermal dysplasia mutations in Brazilian families

X‐linked hypohidrotic ectodermal dysplasia (XLHED) is characterized by severe hypohidrosis, hypotrichosis, and hypodontia. The gene responsible for this pleiotropic syndrome (ED1) consists of 12 exons, 8 of them coding for a transmembrane protein (ectodysplasin‐A; EDA‐A) involved in the developmental process of epithelial–mesenchymal interaction. ED1 mutations that cause alterations in this protein lead to the XLHED phenotype. The major objective of the present study was to detect ED1 mutations in four Brazilian families with the XLHED phenotype and to compare them to the more than 60 different mutations already reported. DNA of the EDA‐A coding exons was amplified by PCR, and single strand conformation analysis (SSCA) of the electrophoretic bands was carried out in polyacrylamide gel stained with silver nitrate. Two of these four families showed altered DNA band patterns. Subsequent DNA sequencing of the two mutated exons showed: (1) a 36 nucleotide deletion at exon 5 responsible for the loss of four Gly‐X‐Y repeats of the collagen subdomain of EDA‐A; (2) a guanine deletion at exon 6 (966 or 967 sites) that alters EDA‐A after amino acid 241 and leads to a premature ending at amino acid 279. This mutation at exon 6 seems not to have been reported previously and determines a truncated EDA‐A without a part of its extracellular domain that contains the whole TNF homologue subdomain. These two DNA mutations are compatible with the XLHED phenotype. In the other two families the PCR–SSCA methodology was unable to detect any mutation responsible for the XLHED phenotype.

A JEWISH ISOLATE IN SOUTHERN BRAZIL. EFFECTIVE POPULATION, INTERMARRIAGE, FERTILITY, INBREEDING, MORTALITY, TWINNING, SEX RATIO, GENETIC LOAD AND TOTAL MUTATION RATE.

Demography, anthropology and population genetics are disciplines with extensive overlapping areas. A number of data collected in each one of them present a considerable interest to the students of the other two. Spuhler (1959) reviewed the most important points where the three fields contact each other. Fertility, mortality, marriage, and migration-the four principal topics quantitatively treated by demographers-are highly important in population genetics. Anthropologists show an increasing interest in population genetics, and human geneticists are, in a number of aspects, looking for the kind of information obtained by anthropologists. It is worth mentioning that even cultural anthropology is an area where a human geneticist may find a good amount of data of relevant importance for his speciality. The present paper (a summary of which has been previously published: Krieger & FreireMaia, 1961) will describe some quantitative aspects of the Jewish community living in Curitiba, the capital of the State of Paran&, Brazil. Curitiba is a modern, rapidly growing city, with about 360,000 inhabitants. It has a heterogeneous population with a number of Germans, Poles, Ukrainians, Italians, Arabians and their descendants. The majority of its population, however, is of distant Portuguese origin. The incidence of Negroes and Mulattoes is extremely low, as compared with other Brazilian cities. The large majority of the population of Curitiba is Roman Catholic, with a minority of Protestants and Spiritualists, including those of the African sect called Umbanda.

Atrichias and Hypotrichoses: A Brief Review with Description of a Recessive Atrichia in two Brothers

A short review of nine different forms of atrichias and hypotrichoses is presented. Two brothers with universal atrichia, the only children of normal consanguineous parents, are described.

Christ-Siemens-Touraine syndrome. Investigations on two large brazilian kindreds with a new estimate of the manifestation rate among carriers

SummaryTwo large Brazilian families with 34 males and 32 females presenting Christ-Siemens-Touraine syndrome are reported. As “unusual” features, one kindred presented two very severely affected girls, nine affected males with a normal nose, and a very heterogeneous trichodysplasia among both males and females; oligohydramnios was verified in the pregnancies of carriers from both kindreds. Carrier detection was possible in 0.73–0.04 of all the cases.

Genetic Investigations in a Northern Brazilian Island

18 albinos were born on Lencois 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

An Ectodermal Dysplasia Syndrome of Alopecia, Onychodysplasia, Hypohidrosis, Hyperkeratosis, Deafness and other Manifestations

A girl is reported with a hitherto apparently undescribed ectodermal dysplasia syndrome. The main findings include: alopecia, onychodysplasia, hypohidrosis, sensorineural deafness, skin with a tan color and hyperkeratosis (involving also plams and soles), unusual facies (with slight auricle and nose abnormalities), pectus excavatum, severe hyperopia, EEG abnormalities, and retarded bone age. The patient also presents mongoloid palpebral slanting, narrow palpebral fissures, bilateral esotropia, photophobia and dermatoglyphics with extensive ridge dissociation. The etiology is unknown but presumed to be genetic, possibly due to the homozygous state of an autosomal recessive mutation.

Population genetics and demography.

This paper presents a general view of the overlapping areas between population genetics and demography; it gives a short analysis of the use of models in population genetics and presents Wright’s clas