Pericentric inversions: studies in 47 cases]

The authors report 47 cases of pericentric inversion. Eleven of them involve the chromosomes No. 2, 11 and 9. It appears that the risk of malformations and/or encephalopathy is obviously increased either by "position effect", aneusomie de recombinaison" or "interchromosomal effect". Prenatal diagnosis is therefore indicated. Thirty six cases involve the secondary constriction of chromosome No. 9. In such cases the risk is not enough increased to justify the prenatal diagnosis.     

Paracentric inversion in man: Personal experience and review of the literature

Summary The personal experience of seven patients with a paracentric inversion is reported, including cytogenetic, clinical, and familial findings. The present knowledge on paracentric inversions in man is reviewed.     

Pericentric inversions of the X chromosome. A new observation and review of the published cases

A pericentric inversion of the X chromosome-inv(X) (p11.3q22) is transmitted in 3 generations. Male and female carriers are normal. The proposita is tetraplegic, severely retarded and suffers from general seizures. Grand mal seizures are known in the mother and grandmother. Different proportions of inactive X chromosomes in the proposita and the normal sister are discussed. The published cases of inv(X) are reviewed.     

Pericentric inversions of chromosome 12 in two families

Summary Two cases of pericentric inversion of chromosome 12 are presented, one 46,XX,inv(12)(p13;q11) and the other 47,XX,+21,inv(12)(p13;q13). In both cases one of the parents was also a heterozygotic carrier of the inversion. These inversions were detected among 4035 cytogenetic analyses carried out in patients with psychosomatic retardation and/or malformations (357 with a Down phenotype) and in patients with histories of miscarriages, sterility, or growth failure.In cases studied from a review of the literature together with our own we found that among 3235 cases of Down syndrome there were 7 patients with trisomy 21 and inherited balanced reciprocal translocation involving chromosomes other than pair 21. The frequent participation of some chromosomes in these balanced reciprocal translocations, above all those of group A (1–3), suggests that these and probably other rearrangements could make the segregation of chromosome 21 easier.     

Infinite models in scoliosis: a review of the literature and analysis of personal experience.

Abstract The purpose of this study was to introduce infinite models in scoliosis and to analyze personal experience. Based on a three-dimensional patient-specific finite element model of the spine, rib cage, pelvis and abdomen, a parametric individual model of a thoracolumbosacral orthosis was built. Three standard strap tensions (20, 40, 60 N) were loaded on the back of the brace to simulate the strap tension. The I-Scan distribution pressure measurement system was used to measure the pressure of the different regions and the equivalent forces in these regions were calculated. The spinal curve changes and the forces acted on the brace generated by the strap tension were evaluated and compared with the measurement results. The reduction of the coronal curvature was approximately 60% for a strap tension of 60 N. The sacral slope and the lordosis were partially reduced in this case. The brace modified the axial rotation at the deformed vertebrae. The forces generated in finite element analysis were in good agreement with the measurement. The findings supported the feasibility of such an approach to analyze individual bracing biomechanics, which may be useful in the design of more effective individual braces.     

Pericentric inversion of chromosome 13: familial study and review of the literature.

A family is described in which a pericentric inversion of chromosome 13 (13(p11 q22] was discovered after amniocentesis was performed in a patient with a previous stillborn child with multiple congenital abnormalities, and one surviving Down syndrome offspring with the maternal inversion and an additional trisomy 21. No association between pericentric inversion of chromosome 13 and other chromosomal abnormalities was found in the literature. This study discuss the possible involvement of this type of inversion in the occurrence of chromosomal and phenotypic alterations in the carrier offspring, as well as its role in genetic counseling and in the indication of prenatal diagnosis.     

Paracentric inversions in man

Summary The Leuven cytogenetic center experience on paracentric inversions in man is discussed. From a total of 51,000 patients, referred for constitutional chromosome analysis during the period 1970–1985, paracentric inversions were found in 18 index patients. A puzzling finding is the high incidence (26%) of mental retardation and/or congenital malformation in the inversion carrier offspring of phenotypically normal parents with identical chromosomal rearrangements. There was also a high incidence of early fetal loss in the inversion carrier parents. This finding may be explained by an increase of chromosomally unbalanced gametes which result from crossing-over in the meiotic inversion loop. Finally, the possibility of an increased tendency to non-disjunction in paracentric inversion carrier parents is discussed. The most frequent paracentric inversion was inv(3)(p13p25); it was detected in seven unrelated index patients. According to the present experience and the literature data, the breakpoints in paracentric inversions seem to occur preferentially at 1p22, 1p36, 3p13, 3p25, 7q11, and 7q22 regions.     

Pericentric inversion of the X chromosome: presentation of a case and review of the literature.

A large pericentric inversion of the X chromosome [inv(X)(p22.31q26.3)] was found to be transmitted in four generations through phenotypically normal males and females. In one female carrier, the inv(X) was late replicating in 70% of lymphocytes and 46% of skin fibroblasts. Steroid sulfatase (STS), an enzyme which normally escapes inactivation has been located to Xp22.32 and, in our case, has been moved to an aberrant position. We have assayed its activity in clones with the inv(X) inactive or the normal X inactive and found no significant differences. Thus, the STS locus escaped X inactivation in both the normal and the inverted X chromosomes. A review of the literature shows that almost half of the breakpoints on the short arm are found at region p22 and we propose that low-copy repetitive DNA segments along the X chromosome are responsible for non-homologous pairing and production of inversions.     

Paracentric inversions: a review

This review of paracentric inversions in man includes what we know of the behaviour and reproductive consequences of paracentric inversions from other species. Observations of naturally occurring inversions in several species of plants and animals and results of experiments with mutagenically induced inversions in the mouse are discussed. From a review of 184 cases, it is concluded that most of the paracentric inversions in man are harmless and that the risk of heterozygotes having a child with an unbalanced karyotype is low. However, in some cases, it is difficult, if not impossible, to distinguish between a paracentric inversion and a paracentric insertion, the risk in the latter case being about 15%. Caution is also necessary in interpreting the results of prenatal diagnosis for heterozygotes of paracentric inversions, because of the possibility of a variety of unpredictable unbalanced chromosome products.     

Immune and autoimmune disorders in HCV chronic liver disease: personal experience and commentary on literature

HCV chronic liver disease can be associated with a plethora of immune and autoimmune perturbations and many authors claim that HCV chronic infection can play an important role in the pathogenesis of these disorders. To compare our experience with literature reports, we performed a retrospective study on the case histories of 265 patients with HCV chronic liver disease, evaluating the type and prevalence of the associated immune and autoimmune manifestations. We found that the patients with HCV chronic liver disease can present arthromyalgias (7.1% of the patients), Sj?rgen's syndrome (5.2%), thyroiditis (4.1%), rheumatoid arthritis (2.2%), autoimmune thrombocytopenia (2.6%), mixed cryoglobulinemia (1.5%), autoimmune anemia (0.3%) and oral lichen planus (0.3%). We claim that HCV liver infection is able to induce immune and autoimmune perturbations, without playing a significant role in the pathogenesis of a well-defined disorder.     

Arrhythmogenic dysplasia of the right ventricle-- clinical picture in view of the literature and personal experience

The author discusses arrhythmogenic dysplasia of the right ventricle, a disease of unclear etiology characterized by the replacement of right ventricular muscle with the connective tissue and ventricular cardiac arrhythmias. Clinical symptoms, available diagnostic techniques and treatment are reviewed. Four case reports illustrate arrhythmogenic dysplasia of the right ventricle.     

Pasteurella multocida infection in man; a review of the literature

Pasteurella multocida has been isolated from infected lesions of nearly all regions of the body. Cat and dog bite wounds are frequently infected by this organism. The severity of the lesion varies from trivial sepsis to a severe wound abscess with sloughing and septicaemia. Bone involvement is frequent. Despite the apparent sensitivity of the organism to a wide range of antibiotics, chemotherapy may be of little avail. Frequently, extensive débridement and skin grafting is required. In the respiratory tract, the clinical picture extends over bronchitis, bronchiectasis, pneumonia, empyema, otitis media, mastoiditis and sinusitis. In these latter infections a history of contact with animals may not be elicited. Examination of the patient's serum may not be helpful as antibody titers are often low, even in the presence of severe acute infection.     

Paracentric inversions in man. Apropos of 2 familial observations

Two observations of paracentric inversion in man are reported. One is located on the long arm of chromosome 1 and was observed over two generations. The other is on the long arm of chromosome 5 and was transmitted over three generations. The possible implications of paracentric inversions on the phenotype and fertility are discussed.