Chromosome 11 segmental paternal isodisomy in amniocytes from two fetuses with omphalocoele: new highlights on phenotype-genotype correlations in Beckwith-Wiedemann syndrome.

BACKGROUND: The phenotypic variability in Beckwith-Wiedemann syndrome (BWS) reflects the genetic heterogeneity of the mechanism which by default leads to the deregulation of genes located at 11p15.5. Genotype-phenotype correlation studies have demonstrated an association between omphalocoele and CDKN1C/p57 mutations or hypermethylation. Paternal uniparental disomy 11 (pUPD11) has been described only in the mosaic condition with both uniparental and biparental cell lines, and no association with omphalocoele has been pointed out. METHODS: Two cases are presented here, in which a paternal segmental UPD11 was detected by molecular investigation of amniotic fluid cell cultures after the presence of apparently isolated omphalocoele was revealed in the fetuses by ultrasound scan. Further studies were performed on additional autoptic feto-placental tissues to characterise the distribution of the uniparental cell line and to unmask any biparental lineage in order to document in more detail the as yet unreported association between omphalocoele and pUPD11. RESULTS: Results on the UPD distribution profile showed that the abdominal organs have a predominant uniparental constitution. This condition could mimic the effect of CDKN1C/p57 inactivation, causing the omphalocoele. CONCLUSION: New genotype-phenotype correlations emerge from the investigated cases, suggesting that molecular analysis be extended to all cases with fetal omphalocoele in order to establish the incidence of pUPD11 in complete BWS and in monosymptomatic/mild forms.

Novel mutations of ubiquitin protein ligase 3A gene in Italian patients with Angelman syndrome.

Angelman syndrome is a neurobehavioral disorder caused by defects of imprinted gene(s) on chromosome 15q11-13. AS-specific DNA methylation is found in patients carrying 3-4 Mb deletions ( approximately 70%), paternal uniparental disomy (3-5%) or imprinting center mutations (2-9%), while normal methylation pattern with biparental inheritance characterizes the remaining approximately 20-25% AS patients (Stalker et al.,1998; Tsai et al.,1998). Mutations in the Ubiquitin protein ligase 3A gene (UBE3A) have been found in the latter group, but only preliminary figures are available on their frequencies. We selected a sample of 25 AS patients with a clinical diagnosis of AS and a normal methylation pattern in order to search for mutations of the UBE3A gene. Automated sequencing of exons 8, 9, 10, 11 and 12 performed on our 25 patients allowed us to identify three novel mutations: an 897insA in two unrelated familial cases, a 2544insA and an E167X in two sporadic cases. Mutation R482X previously reported in a sporadic patient was identified in a third familial case. Hum Mutat 15:387, 2000.

Pure 6p22-pter trisomic patient: refined FISH characterization and genotype-phenotype correlation.

First described in 1971, partial trisomy 6p is uncommon and generally secondary to a familial reciprocal translocation. The proximal breakpoint of the reported cases varies from p11 to p25. We here report on a patient with moderate mental retardation, craniofacial and pigmentary anomalies, proteinuria, and hyperglycemia who was found to have a mosaic karyotype 46,X,add(Y)(q12)/45,X. Fluorescence in situ hybridization (FISH) enabled us to identify that the additional material on Yqh derived from 6p and to define the rearrangement as der(Y)t(Y;6)(q12;p22). To the best of our knowledge, this is the first case of trisomy 6p22-pter without an associated deleted segment; the second breakpoint of the rearrangement is in Yqh. Precise mapping of the centromeric breakpoint of the trisomic 6p segment allowed a more convincing correlation between partial 6p trisomy and clinical phenotype to be addressed. In particular, the proteinuria often observed in 6p trisomic patients could be assigned to the 6p22-6pter region.

Apparent CHARGE association and chromosome anomaly: chance or contiguous gene syndrome.

This report concerns 2 unrelated patients with apparent CHARGE association and a chromosome abnormality, resulting from different unbalanced familial translocations involving chromosomes 2 and 18 in one family, and chromosomes 3 and 22 in the other. Although the identification of two different chromosome abnormalities might be due to chance, the observation of a long arm deletion of chromosome 22 in patients 2 and of the frequent coexistence of CHARGE association and DiGeorge anomaly raise the possibility of a contiguous gene syndrome in at least some CHARGE cases.

Prenatal testing in a fetus at risk for autosomal dominant polycystic kidney disease and autosomal recessive junctional epidermolysis bullosa with pyloric atresia.

Amniocentesis and fetal skin biopsies were performed at 18 weeks of gestation in a fetus at risk for autosomal dominant polycystic kidney disease (ADPKD) and autosomal recessive junctional epidermolysis bullosa (EBJ) with pyloric atresia. A previous son of the couple under investigation had died at 3 months of EBJ. The mother of the propositus has ADPKD. Genetic linkage studies were carried out in 11 relatives (4 with ADPKD), and on fetal DNA obtained from cultured amniocytes, using 8 flanking DNA markers tightly linked to the PKD1 locus on chromosome 16p, and a DNA marker linked to another putative ADPKD locus on chromosome 2p. The linkage results indicated that the fetus had not inherited the ADPKD chromosome from the affected mother, with a diagnostic accuracy of > 99%. Ultrastructural and immunohistochemical analyses of multiple fetal skin biopsies showed no EBJ-associated abnormalities. Thus, combining recent morphological and molecular diagnostic methods, we could show that the fetus was free from both diseases. After 40 weeks of gestation, a normal male infant was delivered.

How wide is the clinical spectrum of the acrocallosal syndrome? Report of a mild case.

A boy presenting with an incomplete form of the acrocallosal syndrome is described. The syndrome shows clinical variability and it is stressed that none of the components is constant and facial dysmorphism is not always characteristic.

Theoretical recurrence risks for cleft lip derived from a population of consecutive newborns.

Theoretical recurrence risks for cleft lip with or without cleft palate (CL(P)) were calculated from heritability estimates derived from a population of 203 newborns with CL(P) in a total of 220,927 consecutive births in north-east Italy. Birth prevalence of CL(P) and the frequency of CL(P) in relatives of probands were estimated after exclusion of cases with CL(P) resulting from a known cause or pathogenesis. The method allowed estimation of the theoretical recurrence risk for any family by considering the total number of affected and unaffected first, second, and third degree relatives. The lower value of the theoretical risk compared to the empirical risk, obtained from retrospective data of selected families, was the result of methodological differences.

Clinical anophthalmia: an epidemiological study in northeast Italy based on 368,256 consecutive births.

We describe an epidemiological and clinical study of Clinical Anophthalmia in a population of consecutive live and stillborns enrolled in a hospital based registry of congenital malformations in Northeast Italy during the period from 1981 to 1989; 22 cases were detected among 368,256 births yielding a birth prevalence of 0.60 per 10,000 (95% CI 0.34-0.84); 20 cases were associated with at least one other major malformation. Malformation syndrome, association, or sequence was diagnosed in 13, while a non-recognizable multiple defect pattern was observed in 7/20 (35%). A chromosomal anomaly was present in eight syndromic cases. No significant trend over time, nor space or time clusters, were detected. As most CAn cases are associated with other anomalies recognizable by ultrasound, a decreasing trend in its prevalence at birth is expected in the future.

Neurofibromatosis-1: a maximum likelihood estimation of mutation rate.

Methods of classical segregation analysis were applied to a sample of 129 sibships with one or more individuals affected by neurofibromatosis-1 (NF-1). The sample consists only of subjects with NF-1; all the probands had been referred for genetic counselling because of café-au-lait spots, and a diagnostic protocol was invariably applied. No deviation from the segregation ratio expected for a fully penetrant Mendelian dominant gene was observed. A maximum likelihood estimate of the proportion of sporadic cases was obtained, and the mutation rate was estimated to be 6.5 x 10(-5) gametes per generation (95% CI 5.0-8.1).

Linkage analysis of neurofibromatosis type 1. Study of a homogeneous North Italian population with five DNA markers of chromosome 17.

The authors report the results of a genetic analysis performed in 34 neurofibromatosis type 1 (NF1) Italian families using five loci tightly linked to NF1: D17S33, D17S82, D17S83, D17S37, and D17S36. A two-point linkage analysis was performed with the LINKAGE and the CRI-MAP programs. The map of the region was constructed using the MAP90 program. Data from the present study lend further support to evidence that all NF1 mutations are allelic and that the NF1 locus resides in the proximal region of chromosome 17q. Close linkage of NF1 to all the markers was found. Two of them, namely D17S82 and D17S83, showed the highest linkage with a value of 0 recombination frequency and lod scores of 3.77 and 4.02, respectively. The best map found is D17S33-D17S82-NF1-D17S83-D17S37-D17S36+ ++. The authors stress that knowledge of precise order is essential; if D17S82 and D17S83 are proved to flank the NF1 gene, they allow an acceptable presymptomatic diagnosis in informative families.

A new family with extra material on proximal 15q.

Proximal extra material in the long arm of chromosome 15, has been described in individuals with different phenotypes (isolated mental retardation, multiple malformations, repeated miscarriages), and with apparently normal phenotype, in which cytogenetic analysis was invariably carried out on the basis of clinical indications. The paper describes a child with mental retardation, and his father, who both had proximal extra material in 15q. Caution is advised in the study of karyotype-phenotype correlation.

Neonatal growth patterns in a population of consecutively born Down syndrome children.

Percentile charts of neonatal length, weight, head circumference, and weight/length squared have been constructed using data based on 688 consecutive newborn infants with Down Syndrome and 6,890 normal newborn infants (control group) registered in the congenital malformation registers of North-East Italy and the Emilia-Romagna Region. All percentiles of growth variables are lower in Down syndrome than in the control infants, except for the weight/length2 percentiles, suggesting that growth in Down syndrome is prenatally reduced; overweight begins after birth.

Fatal progression of Behçet's disease after cardiac surgery.

The authors describe a patient affected with Behçet's disease who developed, after cardiac surgery, acute clinical manifestations of the syndrome and died of a generalized infection. They also discuss the clinical aspects, the particular clinical course, and the therapy of the disease.

[Energy expenditure during a pregnancy complicated by post-traumatic coma: analysis of 2 clinical cases]. / Spesa energetica in corso di gravidanza complicata da coma post-traumatico: analisi di due casi clinci.

OBJECTIVE: To analyze the measured resting energy expenditure, the clinical evolution and the nutritional therapy of two pregnant women complicated by post-traumatic coma and sepsis. DESIGN: Clinical study. SETTING: The ICU of Neurosurgery in Regional Hospital in Italy. PATIENTS: Two subjects with head trauma due to a motor vehicle accident. METHOD: The resting energy expenditure was measured (M-REE) by indirect calorimetry by oxygen consumption (VO2) and carbon dioxide production (VCO2). Values were controlled in patients with a hemodynamic stability every 4 hours. Predicted REE (P-REE) was calculated according to the Harris-Benedict formula. A total parenteral nutrition (1.2-1.3 x M-REE) composed of dextrose (70-80% of total caloric amount) and fat (20-30%) was infused in both the subjects. As an average 12-15 g of nitrogen were infused daily. RESULTS: VO2 and VCO2 increased during the study (case 1: from 225 +/- 33 to 325 +/- 35 ml/min; p < 0.02; LR: p < 0.0001; VCO2: from 170 +/- 24 to 289 +/- 23 ml/min; p < 0.0001. Case 2: VO2: from 239 +/- 22 to 315 +/- 35 ml/min; p < 0.05; LR: p < 0.01. VCO2 from 177 +/- 31 to 247 +/- 22 ml/min; p < 0.05; LR: p < 0.001). M-REE/kg increased with statistical significance during the study (case 1: from 23.6 +/- 4.1 to 34.1 +/- 4.3, p < 0.05, LR: p < 0.005; case 2: from 23.7 +/- 5.8 to 33.4 +/- 7.7, p < 0.05, LR: p < 0.05). A physiological variation in oxidative capacity on nutritional substrates was reported throughout the study. CONCLUSION: Sepsis and miscarriages following trauma seem to be the cause in an increase of the energy expenditure rather than pregnancy itself. However our observations must be viewed with caution because they are based on a small number of patients.

The effects of prolonged cardiopulmonary bypass on cell-mediated immunity.

Studies of T-cell subsets (CD3+, CD4+, CD8+, CD8+ CD57+ cells), lymphocyte response to concanavalin A (Con A), phytohaemoagglutinin (PHA) and the alterations of white cell membranes shown by scanning electronic microscope (SEM) in 51 patients who underwent cardiac operation were performed. Out of these 51 unselected patients, for 16, duration of CPB was < or = 110 min (group A), while for the other 35 (group B) it was prolonged (> 110 minutes). Although variations of the lymphocyte subset observed between groups A and B were slightly significant (p < 0.05 before CPB and on postoperative day 7), the T-cell reactivity in group B in comparison to that of group A did not normalize by postoperative day 7 regardless of stimulation with PHA or with Con A. With the use of the SEM, the folded aspect of lymphocyte surface decreased after surgery in about 71% (group A) and 78% (group B) of the observed cells. The outcome of the immunological effects given by our studies could have been due to an elongated CPB even if there need to be taken into consideration multifactorial influences, i.e. biological, pharmacological and hormonal hypotheses, and rapid changes in CPB-micro-environment.