Omphalocele and gastroschisis: a collaborative study of five Italian congenital malformation registries

During 1984-1989, 116 cases of omphalocele and 42 cases of gastroschisis were detected among 736,760 consecutive births in the area covered by five Italian congenital malformation registries. The prevalence rate was 1.6 per 10,000 for omphalocele and 0.6 per 10,000 for gastroschisis. Three additional cases were detected among spontaneous abortions, giving a total of 117 cases of omphalocele and 44 of gastroschisis. No variations in prevalence rates were observed among registries. A cluster of omphalocele was found in 1989 in Firenze. All cases were sporadic except for one infant with two sibs with Beckwith-Wiedemann syndrome. A predominance of male infants was observed for both defects. This study confirms the very young maternal age for isolated gastroschisis as compared to that for omphalocele and controls. Birth weight and the percentage of small-for-date is different among isolated gastroschisis, omphalocele and controls. Associated anomalies occurred in 45 cases of omphalocele and 11 cases of gastroschisis. Our data confirm the association of omphalocele with trisomies 13 and 18. Twelve cases of omphalocele and gastroschisis with associated limb defects were classified as limb body wall complex. The possible differences in etiopathology between omphalocele and gastroschisis, both isolated and associated, are discussed.

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.

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.

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.

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.

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).

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.

Aortic elastin abnormalities in osteogenesis imperfecta type II

Skin and aortic samples from two patients who died by lethal perinatal Osteogenesis Imperfecta (O.I.) were studied by optical and electron microscopy and compared with similar samples from two normal human fetuses and one newborn child. No significant abnormalities were observed in the dermis of O.I. patients apart from small differences in the diameter of reticular collagen fibrils. On the contrary, in the aortas of both patients collagen fibrils were significantly smaller than in the controls; moreover, elastin lamellae were deeply altered and consisted of roundish aggregates of elastin, massively permeated by cytochemically recognizable glycosaminoglycans. As identical features were described in experimental lathyrism by using inhibitors of the enzyme lysyl oxidase (Pasquali Ronchetti et al., 1984), the conclusion is reached that in the two cases of lethal perinatal O.I. examined, a severe lysyl oxidase deficiency could account for the observed ultrastructural abnormalities of elastin and that, besides defects of collagen type I, additional alterations of cellular metabolism might be responsible for the clinical heterogeneity of the disease.

Another Italian family with mandibuloacral dysplasia: why does it seem more frequent in Italy?

We describe three patients (one female and two males in a sibship of 11) with mandibuloacral dysplasia. Only eight families have been reported previously, and of these, four were of Italian origin. The phenotypic spectrum of the condition is delineated and its variability is stressed. The observation of three affected members of both sexes with normal parents supports the hypothesis of autosomal recessive inheritance. The reasons for the high frequency of the condition in Italy are discussed; a local selective advantage for heterozygotes and founder effect might be involved.

An inheritable anomaly of red-cell oxalate transport in "primary" calcium nephrolithiasis correctable with diuretics

We measured the rate of oxalate flux across the red-cell membrane in the steady state in 114 patients with a history of calcium oxalate kidney stones and in 25 controls. Of the patients, 98 had recurrent, "idiopathic" kidney stones, 8 had primary hyperparathyroidism, 7 had renal or urinary tract malformations, and 1 had primary hyperoxaluria. Oxalate exchange was significantly higher in the 98 patients with idiopathic stone formation than in the controls (-1.10 +/- 0.95 [SD] X 10(-2) min-1 vs. -0.31 +/- 0.12 X 10(-2); P less than 0.001); it was above the upper limits of normal in 78 of these patients. All 8 patients with hyperparathyroidism and the patient with primary hyperoxaluria had values in the normal range; 2 of the patients with renal or urinary tract malformation had values at the upper normal limit. A study of five families indicated that the abnormality is an autosomal monogenic dominant trait with complete penetrance and variable expressivity. Oxalate-tolerance tests were carried out in five pairs of brothers. One brother in each pair had the abnormality in oxalate flux, and had a significantly higher percentage of oxalate excretion at two hours after oxalate loading (18.09 +/- 3.07 [SD] vs. 10.37 +/- 3.08 percent; t = 3.97; P less than 0.005) and four hours (14.87 +/- 2.91 vs. 9.89 +/- 2.93 percent; t = 2.70; P less than 0.05). Treatment with oral hydrochlorothiazide (50 mg per day) or amiloride (5 mg per day) or both restored normal or nearly normal red-cell oxalate exchange in all of 33 patients who initially had increased rates. We conclude that an inherited cellular defect in oxalate transport may be a factor in "primary" calcium oxalate stone formation and that this defect may be corrected with diuretics.

Pachyonychia congenita Jackson-Lawler type: a distinct malformation syndrome

A family with three members in two generations affected by pachyonychia congenita, hyperkeratosis and hyperhidrosis of the palms and soles, follicular keratosis, neonatal teeth and epidermoid cysts (Jackson-Lawler syndrome) is described. The nosological autonomy of this condition is proposed and a further heterogeneity is suggested on the basis of histopathological changes in the subcutaneous cysts.

Microphthalmia-congenital anterior polar cataract. An autosomal dominant syndrome

A condition is described which is characterized by microphthalmia and congenital anterior polar cataract, transmitted in an autosomal dominant fashion.

Frequency of consanguineous marriages among parents and grandparents of Down patients

The existence of a rare autosomal gene which in the homozygous state would cause mitotic nondisjunction in the Down zygote has been hypothesized in the past by Alfi et al. (1980). This hypothesis can be supported or contradicted by the study of the frequency of consanguineous marriages among parents of affected children. Our study on 242 children affected with Down syndrome does not show any increase in the frequency of consanguineous marriages among their parents with respect to the general population, and therefore does not support the hypothesis of an autosomal gene controlling mitotic nondisjunction. Our data do not show any increase in the frequency of consanguineous marriages even among paternal and maternal grandparents of the affected children, thus not supporting the other possible explanation of an autosomal recessive condition in one of the patient's parents which would cause meiotic nondisjunction.

Popliteal pterygium syndrome presenting with orofacial abnormalities. Report of a family

A family with popliteal pterygium syndrome is reported: two children presented a mild form of the syndrome, while their mother exhibited full expression of the gene. Only 11 families with 29 affected members and 25 sporadic cases have been published. This malformation syndrome is inherited in an autosomal dominant pattern, but environmental factors or genetic heterogeneity cannot be excluded in sporadic occurrences. The variability of expression is discussed and a comparison with previously published familial cases is made: minor anomalies, if present in relatives of patients with full gene expressions, are as helpful in making the diagnosis as are major abnormalities. Careful evaluation of the proband's family is essential for diagnosis and subsequent genetic counselling.

Frequency of abnormal karyotypes in relation to the ascertainment method in females referred for suspected sex chromosome abnormality

Cytogenetic investigation was carried out on 231 female patients referred for suspected sex chromosome abnormality. Cases were classified into five groups according to reason for referral and chromosome abnormality frequency was estimated. The overall frequency of abnormal karyotypes was 38.5%. The rate of positive identification of chromosome abnormality ranges from 0 in patients with secondary amenorrhoea to 80% in those with Turner phenotype. Our data demonstrate that the indications for referral of female patients with suspected sex chromosome abnormality are not only primary amenorrhoea alone or short stature and primary amenorrhoea without Turner stigmata, but also short stature of unknown etiology without any additional anomaly during childhood.

Ring chromosome 21 in phenotypically apparently normal persons: report of two families from Switzerland and Italy

If a ring 21, originating from breaks close to the telomere of 21q and anywhere in 21p, replaces a normal 21, it may be associated with an apparently normal phenotype. An apparently normal mother and son were ascertained by a prenatal chromosome study. A second mother, with a ring 21 but without gross anomalies, is short of stature, has epilepsy and has a low normal intelligence. He daughter is a mosaic: 46,XX/47,XX,+r(21) and has the Down's syndrome. None of these four persons was found to have mitoses with more than one ring 21 or with rings of double size.

Replication patterns of human X isochromosomes by high-resolution banding

The DNA replication patterns of eight cases of X isochromosomes, five idic(X) and three i(Xq), were studied. R-banded prometaphases and metaphases from lymphocyte cultures after synchronization with methotrexate and incorporation of 5-bromodeoxyuridine were analyzed. No significant differences in the frequency of metaphases with symmetric and asymmetric replication patterns between dicentric and monocentric isochromosomes were found. Furthermore the distribution of the frequencies of R-positive bands was similar and comparable to that of the normal late-replicating X. Our data suggest that the DNA replication pattern of Xq isochromosomes is not correlated with the mechanism of their origin.

Cytogenetic findings in 4952 prenatal diagnoses. An Italian collaborative study

The development of prenatal diagnosis in Italy was made difficult by the restrictions of the old abortion law and only in recent years has a consistent number of cases been investigated. We report the experience on prenatal chromosome diagnosis of ten Italian centers participating in a collaborative study on 4952 diagnoses performed from 1972 to 1980. The main indication groups were: advanced maternal age (2882 cases), previous child with chromosome anomaly from parents with normal karyotype (847 cases), and chromosome anomaly in one parent (97 cases). The other indications for amniocentesis, including cases without a cytogenetic risk, have been assembled into a "miscellaneous" group (1126 cases). We found 125 abnormal fetal karyotypes (2.5%) of which 89 were unbalanced (1.8%). The frequencies and types of chromosome anomalies are reported in detail for each indication group and are compared with the corresponding one from the European Munich Conference. The great majority of these Italian data were not included in the Munich report.

The "cat eye syndrome": dicentric small marker chromosome probably derived from a no.22 (tetrasomy 22pter to q11) associated with a characteristic phenotype. Report of 11 patients and delineation of the clinical picture

Eleven patients with the so-called Cat Eye syndrome are reported including a more detailed description of the original cases reported by Schmid and Fraccaro. All cases had, in addition to a normal karyotype, a small extra G-like chromosome which appeared to be an isochromosome for the juxtacentromeric region (pter to q11) of an acrocentric chromosome. None were mosaics. Clinical findings and further cytogenetic studies in a few cases suggest that these markers probably derive from a No. 22 chromosome. Characteristic features of the Cat Eye syndrome in these 11 patients and those reviewed from the literature are: ocular coloboma which may involve the iris, choroid and/or optic nerve, preauricular skin tags and/or pits which are probably the most consistent feature, congenital heart defect, anal atresia with a fistula, renal malformations such as unilateral absence, unilateral or bilateral hypoplasia, and cystic dysplasia, and antimongoloid position of eyes. Intelligence is usually low-normal, although moderate retardation is also seen. There is great variability in the clinical findings ranging from near normal to lethal malformations. Less frequent, but also characteristic findings are: microphthalmia, microtia with atresia of the external auditory canal, intrahepatic or extrahepatic biliary atresia and malrotation of the gut. Direct transmission of the marker from one generation to the other was observed in both sexes. In those families, there was considerable variability in the clinical findings between affected family members. These cases show that there is a bias of ascertainment for patients who have the more striking malformations, especially those with ocular coloboma and anal atresia, a combination which appears to be present in only a minority of cases. Many mildly affected patients probably remain undetected. It is proposed that the term Cat Eye syndrome should be applied only to cases with trisomy or tetrasomy of not more than 22pter to q11 and without additional duplication or deletion of another autosomal segment.

Study on segregation and risk for abnormal offspring in carriers of pericentric inversion of the (p11 leads to q13) segment of chromosome 2

Pericentric inversion of chromosome 2 was detected in four unrelated families. All these inversions involved the segment p11 leads to q13. The pedigree data are considered in comparison with other cases reported in the literature. Segregation data and possible reproductive failures are discussed.

Trisomy 12p due to an adjacent 1 segregation of a maternal reciprocal translocation t(12;18) (p11;q23)

A 5, 9-12-year-old with trisomy 12 pdue to a maternal reciprocal translocation adjacent 1 segregation is presented. Comparison of his phenotype with that of other patients reported in the literature confirm the existence of a trisomy syndrome.

Syndrome +12p. Case report and review

Familial 12/15 translocation with a child trisomic for the short arm of chromosome 12 (segment of 12.1 leads to pter) is reported. The clinical picture of the child is strikingly similar to previous reports of 12p trisomy. The main symptoms of 12p syndrome are defined.

[Localization of the gene of the glyceraldehyde 3 phosphate dehydrogenase on the distal segment of the short arm of the chromosome 12]

The enzymatic activity of G3PD and LDH-B in erythrocytes has been assayed in three patients carrying a rearrangement of the short arm of chromosome 12. The first patient is trisomic for the whole short arm. The second is trisomic only for the distal part and the third is monosomic for the proximal part. G3PD: Activity increased in patients 1 and 2 and normal in patient 3. LDH-B: Activity increased in patients 1 and 2 and decreased in patient 3. From these observations it is concluded that the erythrocytic G3PD locus is localized on the distal part of 12p, between 12p12.2 and 12 pter, and that LDH-B locus is on the middle third between 12p12.1 and 12p12.2

Trisomy 4q32 leads to 4qter due to a maternal 4/21 translocation

The case is described of a malformed girl with partial trisomy for a segment of the long arm of chromsome (4q32 leads to qter) due to an unfavourable segregation of a maternal reciprocal translocation t(4;21) (q32q22). The clinical comparison between the child and patients previously described by other authors does not suggest the existence of a syndrome associated with trisomy 4q+.

Partial deletion of the short arm of chromosome 12(p11; p13). Report of a case

Chromosome analysis of a 15-day old boy with multiple malformations revealed a partial deletion 12(p11;p13).

A new case of trisomy for the short arm of No. 9 chromosome

A new case with trisomy for the short arm of No. 9 chromosome, identified by heat treatment and Giemsa staining is reported. The clinical picture and dermatoglyphic patterns are similar to those previously reported.