Chromosomal breakpoints characterization of two supernumerary ring chromosomes 20.

The occurrence of an additional ring chromosome 20 is a rare chromosome abnormality, and no common phenotype has been yet described. We report on two new patients presenting with a supernumerary ring chromosome 20 both prenatally diagnosed. The first presented with intrauterine growth retardation and some craniofacial dysmorphism, and the second case had a normal phenotype except for obesity. Conventional cytogenetic studies showed for each patient a small supernumerary marker chromosome (SMC). Using fluorescence in situ hybridization, these SMCs corresponded to ring chromosomes 20 including a part of short and long arms of chromosome 20. Detailed molecular cytogenetic characterization showed different breakpoints (20p11.23 and 20q11.23 for Patient 1 and 20p11.21 and 20q11.21 for Patient 2) and sizes of the two ring chromosomes 20 (13.6 Mb for case 1 and 4.8 Mb for case 2). Review of the 13 case reports of an extra r(20) ascertained postnatally (8 cases) and prenatally (5 cases) showed varying degrees of phenotypic abnormalities. We document a detailed molecular cytogenetic chromosomal breakpoints characterization of two cases of supernumerary ring chromosomes 20. These results emphasize the need to characterize precisely chromosomal breakpoints of supernumerary ring chromosomes 20 in order to establish genotype-phenotype correlation. This report may be helpful for prediction of natural history and outcome, particularly in prenatal diagnosis.

[Symptomatic rickets in adolescents]. / Le rachitisme symptomatique de l'adolescent.

Although systematic vitamin D supplementation in adolescents remains debated, rickets is nevertheless a well recognized pathology in this age group. Adolescence is an at-risk period because of rapid growth, insufficient calcium intake and/or vitamin D status. Surveys have shown that calcium intake is insufficient (< 1000 mg a day) in 45% of boys and 71% of girls and that vitamin D status is deficient (25-OH-D < 10 ng/ml). The aims of the study carried out by the Calcium Group of the Société Française de Pédiatrie, were to evaluate the frequency of rickets, and to define the criteria for the adolescent population at risk. Forty-one adolescents with rickets were hospitalized between 1985 and 2000. Most of the cases were from the Northern France: 20 from Paris and suburbs, eight from the North-West, four from the North, four from the North-East; five were from the Center of France. The mean age was 13 years and two months for the 28 girls, and 14 years and four months for the 13 boys. Eighty per cent of the adolescents were from immigrant families (33/41): 15 were from sub-Saharan Africa, ten from North Africa, six from Pakistan and two from Turkey. Two thirds of the adolescents were hospitalized in the 2nd quarter of the year. Some adolescents suffered from lower limb pain, 16 had deformations of lower limbs, particularly genu valgum, associated with pain; seven others had either muscle spasms (4), tetany (3). Serum calcium level was low (average 1.84 mmol/l: [1.1-2.5]), and serum 25-OH D level was extremely low. Radiographic characteristics observed were metaphyseal strips on the knees, with condensed edges at times, with the presence of bone demineralization. The treatment combined calcium and vitamin D, and was often administered intravenously when a hypocalcemia was detected. Rickets is not frequent in adolescents, but nonetheless this pathology is not exceptional, and the number of cases is probably under-estimated. Rickets affects immigrant adolescents in particular but nevertheless could also present a certain risk period for the general population.

[Epidemiologic survey of infants hospitalized for bronchiolitis. Survey conducted by the ERBUS medical network]. / Surveillance épidémiologique hospitalière de la bronchiolite du nourrisson par le réseau ERBUS.

BACKGROUND: Acute infant bronchiolitis is a frequent seasonal disease which peaks in December. It often requires hospital care in Paris and in its surroundings. The exceptional bronchiolitis epidemic of December 1991 brought about a temporary saturation of hospital bed space at the Assistance Publique-Hôpitaux de Paris (AP-HP). Hereafter, in order to organize care more efficiently, an epidemiological observation network called ERBUS was set up. METHODS: Thanks to daily reports of emergency pediatric admissions through the Minitel network, it has been possible to get real time information on the course of the past five epidemics in each of the 11 AP-HP hospitals with pediatric emergency units. RESULTS: Globally the results point to a similar situation every year: approximately 60% boys, 35% babies under 6 months; the ratio of very young patients who are admitted to hospital is multiplied by 1.5 at the mid-point of and at the end of the epidemic compared with the beginning; 70% of the babies under 3 months are admitted to hospital. The ratio of patients who come and are admitted to hospital has been on the decrease every year since 1991: globally from 36.8% down to 28.6% in five years (from 75.1% down to 65.3% among babies under 3 months). The rhythm and intensity of the epidemic have risen sharply: in five years, the number of patients has increased by 119% and that of patients admitted to hospital by 69%, while the epidemic peaks are earlier and higher. CONCLUSION: These statistics have actually been used to allocate additional resources in AP-HP hospitals during the epidemics. To avoid the saturation of bed space in the future, ambulatory care of patients not admitted to hospital should be favored.

[Laurence-Moon (Bardet-Biedl) syndrome with growth hormone deficiency]. / Syndrome de Laurence-Moon (Bardet-Biedl) avec déficit en hormone de croissance.

BACKGROUND: The features of Laurence-Moon syndrome vary widely from mental retardation, hypogenitalism to retinopathy; the dominant one is progressive neurological involvement, ataxia and spastic paraplegia. Like Bardet-Biedl syndrome, its inheritance is autosomal recessive. This paper describes the endocrine investigation of a new family of Laurence-Moon syndrome subjects. CASE REPORT: The 5 patients (3 girls, 2 boys) in this family of 12 sibs, all suffered from retinopathy, mental retardation and first metacarpal hypoplasia with proximal placement of thumb. All five had had spastic paraplegia since the age of 5-6 years, growth retardation and hypogonadism. Two had had seizures; only one was obese. RESULTS: Four patients (2 girls, 2 boys, aged 19, 15, 18 and 19 years) had low basal plasma FSH and LH levels. They had no FSH-LH response to gonadotropin-releasing hormone; their plasma testosterone and oestradiol concentrations were very low. The growth hormone peak in response to arginine-insulin were low in these 4 patients (1.5 ng/ml; 3.8 ng/ml; 5 ng/ml; 4.8 ng/ml). One boy and one girl were given sex steroids for a few months, with good effect on their sexual characters. Their growth hormone levels remained low (2.9 ng/ml, 6.5 ng/ml). One boy was given FSH and LH analogues with good effects on sexual characters and testicle growth. He was also given growth hormone, and had a growth spurt of 5.5 cm after 9 months treatment. CONCLUSION: The hypogonadism of Laurence-Moon patients seems to be of central origin. It is associated with growth hormone deficiency.

[Diabetes mellitus, diabetes insipidus, optic atrophy and deafness]. / Diabète sucré, diabète insipide, atrophie optique et surdité.

In France, the combination of diabetes insipidus, diabetes mellitus, optic atrophy, and deafness (DIDMOAD) is designated as Wolfram syndrome. An analysis of 14 personal cases and previous reports showed that the syndrome develops gradually and specified the most common order of occurrence of the various components as well as the other abnormalities (e.g., of the urinary tract) which may be found. Wolfram syndrome is an inherited condition (recessive autosomal transmission). The lack of association with HLA antigens seems to have been established (in the few cases where HLA typing was performed). The prognosis of Wolfram syndrome is grim, with the occurrence of each additional component adding to the severity of the disease.

[Proteus syndrome]. / Le syndrome de Protée (Proteus syndrome).

Two new cases of Proteus syndrome are reported. This congenital syndrome, first described in 1983, comprises gigantism of extremities, body hemihypertrophy, pigmented nevi and multiple tumors (subcutaneous, lipomas, hamartomas). This syndrome belongs to the same group as Recklinghausen disease, Maffucci or Klippel-Trenaunay syndromes. The prognosis is not well known but mostly depends on functional and psychologic consequences of important deformations.

[Isolated and transient hyperphosphatasemia in young children]. / L'hyperphosphatasémie isolée et transitoire du jeune enfant.

This report concerns a transient and isolated hyperphosphatasemia in a 33 month-old infant. Such a case is asymptomatic and benign. There is an important increase in enzymatic activity which includes both fractions (bone and liver). Pathophysiology is still unclear. This biological data is worth being known in order to avoid useless and always normal investigations.

[Neonatal hyperinsulinism, congenital corporeal hemihypertrophy, tumor of the breast in adolescence]. / Hyperinsulinisme néonatal, hémihypertrophie corporelle congénitale, tumeur du sein à l'adolescence.

The authors report the association of neonatal hyperinsulinism (nesidioblastosis) and congenital hemihypertrophy in an infant. At the age of 13 6/12 years fibro-adenomas of the breast occurred. The diagnosis of Beckwith-Wiedemann syndrome is discussed.