Erfelijkheidsvoorlichting : van Mendel naar klinische genetica

Rede bij de openbare aanvaarding van het ambt van lector in de Anthropogenetica aan de faculteit der Geneeskunde van de Erasmus Universiteit Rotterdam op woensdag 20 februari 198

Prenatal diagnosis of congenital diseases

Prenatal diagnosis of a number of congenital diseases is possible by amniocentesis in the 14th - 16th week of pregnancy and subsequent analysis of cultured amniotic fluid cells or amniotic fluid supernatant. Parents at risk for a child with a chromosomal disorder, an X-linked disease, a neural tube defect or a metabolic disease may use this new tool in genetic counseling to limit their further offspring to unaffected children by requesting termination of a pregnancy when a fetal abnormality has been detected. The present thesis describes methodological studies in the field of prenatal diagnosis of metabolic diseases and clinical applications of prenatal monitoring in a series of 350 pregnancies with an elevated risk for a chromosomal aberration, an X-linked disease, a metabolic genetic disorder or a neural tube defec

Prenatal diagnosis by ultrasound in pregnancies at risk for autosomal recessive polycystic kidney disease

Abstract In 15 pregnancies at risk of the autosomal recessive type of polycystic kidney disease (ARPKD), there were six recurrences (40%), five of which were diagnosed prenatally between 17 and 26 weeks (mean, 22 weeks). In the remaining affected case, normal kidney size and echogenicity were still present at 30 weeks of gestation. Fetal kidney enlargement and increased echogenicity are the key ultrasonographic signs for the detection of ARPKD. Absent fetal bladder filling and oligohydramnios were only documented in two of the six affected pregnancies. The variability in onset, the intrafamilial variability and the limitations of excluding ARPKD by second trimester ultrasound have to be considered when counselling a couple at risk for this particular disorder

Prenatal diagnosis of type A1 brachydactyly

Brachydactyly can occur as an isolated malformation or as part of numerous syndromes. Prenatal assessment of brachydactyly may be especially helpful in multiple anomaly syndromes associated with hand and/or finger anomalies. In isolated type A1 brachydactyly, which is an autosomal dominant disorder, all middle phalanges of the fingers and toes are affected. We present a fetus with type A1 brachydactyly inherited from the mother and grandmother

Dilemmas in counselling females with the fragile X syndrome

The dilemmas in counselling a mildly retarded female with the fragile X syndrome and her retarded partner are presented. The fragile X syndrome is an X linked mental retardation disorder that affects males and, often less severely, females. Affected females have an increased risk of having affected offspring. The counselling of this couple was complicated by their impaired comprehension which subsequently impaired their thinking on the different options. The woman became pregnant and underwent CVS, which showed an affected male fetus. The pregnancy was terminated. Whether nondirective counselling for this couple was the appropriate method is discussed and the importance of a system oriented approach, through involving relatives, is stressed

The cystic fibrosis defect approached from different angles - New perspectives on the gene, the chloride channel, diagnosis and therapy

Abstract The search for the basic defect in cystic fibrosis (CF) has reached a decisive stage since the recent identification of the responsible gene. Electrophysiological and biochemical research had defined the CF defect as a dysregulation of epithelial chloride channels. The putative protein product of the now identified gene shares properties with other known transport proteins, but it is not necessarily itself a chloride channel protein. Elucidation of the primary cellular defect will certainly have important aetiological and hopefully therapeutic implications. The identification of the major gene mutation already has significant consequences for genetic counselling and prenatal diagnosis. Heterozygote detection at the population level awaits identification of the probably heterogenous mutations on about 30% of the CF chromosomes. At present, about 50% of CF patients are homozygous for the recently identified major CF mutation