[Restriction fragment length polymorphisms in the families of patients with Down's syndrome (trisomy 21)]. / Polymorfismy délek restrikcních fragmentu v rodinách pacientu s Downovým syndromem (trisomie 21).

Using the method of polymorphisms of lengths of restriction fragments (RFLP), the authors compare agreement and differences in the normal healthy Czech population and in families with a patient suffering from Down's syndrome. 2-alpha-satellite DNA probes were used which are weighed in the pericentromeric area of heterochromatin of the long arms of chromosomes 13 and 21. These probes contain a number of repetitive sequences, most frequently represented in human heterochromatin of the majority of chromosomes. By hybridization with an alpha-RI-6 probe multiallelic polymorphisms were obtained in families with Down's syndrome in five restrictive endonucleases (Bsp RI, Eco RI, Pst I, Taq I and Xba I). Restrictions with enzymes Bam HI and Hind III were non-polymorphous. Hybridization with the alpha-RI-IB probe revealed polymorphism with restrictive endonuclease Taq I. Enzymes Bam HI, Eco RI, Hind III, Pst I and Xba I (3) were non-polymorphous. The difference of the two probes in the centromeric area of chromosomes 13 and 21 was confirmed by hybridization in situ, using 3H-labelled thymidine triphosphate (TIP) in quantitative experiments on short-term cultures of lymphocytes of healthy subjects (4).

[Partial trisomy of the short arm of chromosome 3. Case report and phenotype expression]. / Partielle Trisomie des kurzen Arms von Chromosom 3. Fallbeschreibung und Expression des Phänotyps.

A female infant with partial trisomy 3p, facial dysmorphism, cleft palate and severe psychomotor retardation is described. Cytogenetic evaluation revealed a paternal balanced translocation which could also be detected in three relatives of the father. The observed clinical features of the patient are discussed by comparison with 47 previously reported cases.

[Partial trisomy 1q25-1q32 in a boy with isolated lactase deficiency]. / Parciální trisomie 1q25-1q32 u chlapce s izolovaným deficitem laktázy.

A six-month-old boy with partial trisomia 1q25-1q32. In the phenotype psychomotor retardation, progeric facial features and general dystrophy dominated. He failed to thrive partly because of milk intolerance due to hypolactasia. This disorder was revealed by histochemical examination of the enterobioptic material. The chromosomal aberration developed as a result of tandem duplication of section 1q25-1q32 de novo; this finding was not published so far in the literature.

[A genetic registry of pregnant women--SEGRAV]. / Genetický registr gravidních zen--SEGRAV.

The authors describe the structure, contents and use of a genetic register of pregnant women examined at the department of medical genetics. They discuss in detail the investigated data and their classification. The programme makes it possible to use a computer for the longitudinal follow up of the course of pregnancy and the implementation of recommended preventive measures and processing of data for medical statistics. Perspectively the register will be used for evaluation of the validity of genetic prognoses and effectiveness of preventive genetic methods. The register is used in routine practice of genetic clinics since September 1986. The authors give also an account of the experience with the genetic register.