The fears concerning potential hazards of man made recombinant DNA have been dismissed and the burden of compelling unnecessary safety regulations has been cleared away. The deciphering of the entire human genome at the nucleotide level is no longer an impossible task. It is based upon the utilization of cloned fragments of DNA used as specific probes. The present catalogue of cloned human genes is still small, but it will expand rapidly in the near future. There are two categories of probes: those corresponding to know genes, and those consisting of random "anonymous" DNA sequences present in genomic libraries. The increasing number of cloned probes will allow us to saturate progressively the entire genome. Medicine will benefit from this progress, first of all with regard to pre-natal and post-natal diagnosis of some genetic diseases and in the field of cancer research.

Two patients with chronic granulocytic leukemia (C.G.L.) undergoing transformation were treated by high dose chemotherapy and total body irradiation followed by autografting of hematopoietic stem cells collected and cryo-preserved at the time of diagnosis. Recovery of hematopoiesis was characterized by disappearance of the Philadelphia chromosome in most metaphases. A new approach of the management of C.G.L. is discussed.

Thirty-eight children, followed in the pediatric Department of Institut Gustave-Roussy, developed second malignant neoplasms. Intervals between the two neoplasms ranged from 1 to 26 years. The second neoplasms were defined as having a different histologic diagnosis than the first ones: osteosarcoma, fibrosarcoma, thyroid carcinoma, leukemia were the most frequent second neoplasms. The potential carcinogenic part of chemotherapy and radiotherapy is emphasized. In addition, some genetic susceptibility may enhance the carcinogenic effects of therapy. Nevertheless the incidence of second malignant neoplasms is low. Its estimation is discussed here.

The authors describe a case they have personally seen of pure gonadal dysgenesis with caryotype 46 XY (Swyers' syndrome) in which they found absence of HY antigen. They analysed the descriptions in the literature about this syndrome and show how this antigen is responsible for testicular differentiation. They show the place this syndrome has in the group of syndromes of bands and once again draw attention that there is a great risk of gonadoblastoma development when the Y chromosome is present and especially when the HY antigen is present. This means that these dysgenetic gonads should be removed surgically.

Several questions concerning the diagnosis of medullary carcinoma of the thyroid (MCT) arise from two studies of kindred of a patient with MCT carried out in 1977 and 1983. Diagnosis is based on calcitonin level determination after stimulation by pentagastrine. This method should be proposed for all kindred every time a positive diagnosis of MCT has been made for the first time in a given family. When calcitonin levels are normal it is necessary to repeat this test once a year in all individuals over 5 years of age with a high risk of MCT. Surgical removal should be proposed in cases where calcitonin levels are high. But in practice, this may be difficult and screening must be adapted to each individual case.

A case-control study of the familial prevalence (first-degree relatives) of colorectal carcinoma (CRC) was performed from October 1979 through March 1983 in: (a) 170 consecutive patients with histologically proved rectal (n = 64) or colonic (n = 106) adenocarcinoma; cases of familial polyposis coli and cancer family syndrome were systematically excluded from the study; (b) 170 control subjects, who were free of CRC or colorectal adenoma(s) and matched to patients according to sex and age; (c) 170 consecutive patients with common rectal or colonic adenoma(s), and no evidence of polyposis coli; (d) 100 patients with cancer of various organs, excluding CRC and primary tumours known to be epidemiologically related to CRC. Results of family studies were expressed as "proved" (when the pathological report was received) or "probable" CRC. Eighteen (10.6 p. 100) of the 170 patients with CRC had at least one first-degree relative with past or present proved CRC, and 14 (8.2 p. 100) with probable CRC; the corresponding figures were 3 (1.7 p. 100) proved and 3 (1.7 p. 100) probable CRC in the control group, 14 (8.2 p. 100) proved and 11 (6.5 p. 100) probable CRC in the "adenoma" group and 1 (1 p. 100) and 3 (3 p. 100) in the non-colonic carcinoma group. The relative risk of CRC in close relatives was 6.3 and 4.7 in the CRC and adenoma groups respectively. For the variables studied no significant differences were found between males and females.(ABSTRACT TRUNCATED AT 250 WORDS)

The karyotypes of 103 cases of B cell chronic lymphocytic leukemia were studied following stimulation or establishment of continuous cell lines using the Epstein-Barr virus. In 52 patients metaphases suitable for cytogenetic analysis were obtained; 30 revealed normal karyotypes and 22 abnormal karyotypes. The most frequently encountered abnormalities were 6 cases of extra chromosome 12, 4 cases of structured aberrations concerning chromosome 14, including 2 t(11;14), 4 translocations concerning chromosome 11, and 3 cases of extra chromosome 3. No relationship appears to exist between the abnormalities observed and the clinical profile or prognosis.

The authors report three cases of Ph1-positive chronic myelogenous leukemia (CML) with chromosome no 1 abnormalities. Such abnormalities have seldom been reported: three cases out of 42 in blast crisis and none of the 70 patients in the chronic phase in our series. In case no 1 a translocation: (t(1q;14q) was noted. In case no 2 the rearrangement was more complex: partial duplication of the long arm of chromosome no 1 and presence of a 21q+ corresponding to chromosome no 21 on which a part of the long arm of chromosome no 1 was transferred. In case no 3 a double translocation was noted between chromosomes no 1 and no 11, involving either the p or q arm. A review of the literature shows that abnormalities of chromosome no 1 are more frequent during the blast crisis that in the chronic phase of CML. Chromosome no 1 abnormalities are found in a number of myeloproliferative syndromes but even more frequently in solid tumors. The rearrangement sites are reviewed by the authors. Such rearrangements of chromosome no 1 may indicate an increased potential of malignancy.

Fourteen years after the discovery of cherubism a young woman presented reconstructive granulomas of the maxilla and mandible. Her grandmother and father had had giant cell mandibular tumors.

The authors report the case of a 25 year old man with a differentiated (M5 b) acute monocytic leukaemia resistant to polychemotherapy. The patient died four months after the onset of the disease. Cytogenic studies showed thickening of the long arm of chromosome 11, an abnormality considered until now to be specific for poorly differentiated (M5 a) acute monocytic leukaemias.

Hereditary osteodystrophy of Albright's is a set of hereditary dystrophies associated or not with renal and bony resistance to the parathyroid hormone. Two observations of a true brotherhood are reported. These two patients had in common: short stature, obesity (especially facio-troncular), round face, flat and saddled nose, short neck, early cataract and mental deficiency. One of them showed fourth metacarpals. In these two cases there were cutaneous ossifications, markedly profuse on one of them than the other. These ossifications are a frequent manifestation of the osteodystrophy of Albright's. They appear as cutaneous nodules on any part of the body and are visible, palpable and present on X-ray examination. These ossifications share other phenotypic expressions of the disease and do not seem to be related to the resistance against parathyroid hormone.

Medullary thyroid carcinoma (MTC) is hereditary in 20 to 25% of cases. It is inherited as an autosomal dominant trait. MTC can be considered as a sporadic form only after a clinical and biological survey of the two parents, siblings and children of the patient, using pentagastrin stimulation test. The authors have studied 36 patients from 26 families. Hereditary MTC with different clinical features, were discovered in two kindreds. The systematic investigation leads to the discovery of 7 cases in the first family, and of 3 in the second. The treatment of the disease at the first stage of its evolution has been possible when an early diagnosis had been made, such as in the second family.