Study of aneuploidy in fetal tissues using the fluorescent in situ hybridization (FISH) method in cases of stillborn malformed fetuses without a diagnosis

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The deletions of 22q11--the Portuguese experience.

The patients with a chromosome 22q11 deletion have a variable phenotype which includes DiGeorge (DG) and Velocardiofacial (VCF) syndromes. The aim of the present study is to characterize the phenotype of DG and VCF using facial biometry in 12 portuguese patients. We found 4/12 patients with the DG phenotype: 3/4 had telecanthus, small mouth and retrognathia; 1/4 had telecanthus, short nose with bulbous tip and a normal mouth. These patients had major cardiac defects associated with hypoplastic or absent thymus and monosomy 22q11. We did not find velopharyngeal insufficiency in patients with the so called DG phenotype 8/12 patients had the VCF phenotype: typical facies with variable features. Four of these had velopharyngeal insufficiency and learning disabilities. Four patients had cardiac defects and 5/8 had monosomy 22q11. Probably this clinical variability is due to mutations in critical genes involved in embryonic development.

A collaborative approach to the diagnosis of a lethal short limb skeletal dysplasia.

We report a male infant with a lethal short limb Skeletal Dysplasia, born in a District Hospital in the South of Portugal. Local paediatricians investigated clinical and radiographical data. At the Perinatal Pathology Unit of the Egas Moniz hospital the diagnosis of Atelosteogenesis type II was proposed by the Clinical Geneticist and was supported by histopathological findings. Only a collaborative approach turned possible the diagnosis of this unusual entity. Atelosteogenesis type II and Diastrophic Dysplasia are closely related diseases, with similarities in phenotypic and histopathological presentation. Recently, these similarities were extended to molecular levels. The DNA analysis, in progress, will be able to establish a final diagnosis for this affected family.

Microcomputer based differential diagnosis of dysmorphic syndromes.

Dysmorphic syndromes are characterized by associations of physical abnormalities depending in its diagnosis on the recognition of a particular pattern. Because of their multiplicity, the rarity of some of them, and the frequency of new reports, computerized data bases have proved useful as powerful tools assisting in the differential diagnosis. The role of artificial intelligence methods, in particular Expert Systems, as promising tools in helping physicians to perform a clinical diagnosis is underlined. Using a high level computer language presently used in the artificial intelligence field (Prolog), a microcomputer based system for the differential diagnosis of dysmorphic syndromes is described. Its capabilities and simplicity of use, derived from an efficient and attractive computer interface, are underlined. The need of performance assessment by evaluating its accuracy and usefulness before its introduction into genetic clinical practice is stressed. Finally, for the completeness of the knowledge base, the need of cooperation between international centers is emphasized.