A jumping translocation (5p;15q), (8q;15q), and (12q;15q) (author's transl)]

Three balanced karyotypes (5p;15q), (8q;15q), and (12q;15q) were found simultaneously in a child with the Willi-Prader syndrome. The hypothesis is presented of a "jumping# translocation by affinity of telomeric and interstitial palindromes. The relationship between the Willi-Prader syndrome and a juxtacentric anomaly of the long arm of chromosome 15 is discussed.     

Partial trisomy 14q and familial translocation (2;14) (q12;q13).

A female patient with moderate psychomotor retardation, minor anomalies and proximal trisomy 14q due to segregation of a maternal translocation is reported.     

Partial trisomy 2q and familial translocation t(2;12)(q31;q24)

Summary Report is given of a boy with trisomy of the distal part of the long arm of chromosome 2 (q31ter) due to a balanced 2/12 translocation in the mother: 46,XX,t(2;12) (q31;q24). Other phenotypically normal carriers of this balanced translocation are the patients sister and grandfather. The patient shows a variety of dysplastic signs mainly of the face.     

Translocation (Y;19)(q12;q13) and azoospermia

An azoospermic male with a 46,X,t(Y;19)(q12;q13) karyotype is described. The comparison with 12 similar cases reveals that the Y breakpoints are usually on the long arm whereas the autosomal ones seem to be at random. Since a premeiotic origin is inconsistent with the arrest at diakinesis seen in those cases with meiotic studies, we postulate that a balanced t(Y;A) arises either via a chromatid exchange in the meiotic interphase or through a chromosome exchange in spermiogenesis or at the one cell stage of the zygote.     

Familial translocation t(10;21)(q22;q22)

Summary A family is described with a translocation t(10;21)(q22;q22) transmitted through three generations. This family was studied for the apparition of several miscarriages and two sisters with multiple malformations. Both children had a probably partial trisomy of chromosome 10 and a monosomy of chromosome 21 due to a maternal adjacent-2 meiotic segregation.     

47,XY,+der(11;22)(q23;q12) following balanced translocation t(11;22)(q23;q12)mat

Summary Report of a supernumerary extra chromosome der(11;22)(q23; q12) resulting from a balanced translocation in the mother. The propositus suffers from mental deficiency, deafness and extreme muscular weakness and exhibits cleft palate, a labial lymphangioma and an atrial septum defect. Since the features of partial trisomy 11q23 frequently associated with a translocation t(11q;22q) bear similarities with the cases of so called trisomy 22 one might conjecture that some of these observations are in fact products of translocations including partial 11q.     

Translocation 11q;22q: a clinico-cytogenetic study]

Seven families with translocations t(11; 22) identified at our Institute and analysis of the literature showed that the imbalance resulted from such translocations is always due to nondisjunction 3:1. Nondisjunction occurs more often in the 1st meiotic division, and is more rare in the second one. Expressed prezygotic selection against spermia with an additional chromosome greatly increases the risk of having an imbalanced child for the women-carriers as compared to men-carriers. The phenotype of the patients with +der(22)t(11; 22) is composed of the features characteristic for trisomy 22q (cleft lip and palate, preauricular papillomas and fistulas, rectal atresia or stenosis) and trisomy 11q (long philtrum with the upper lip hanging over, renal al; asia and hypoplasia). Diaphragmatic hernias are found to be common for the patients with +der(22)t(11; 22).     

Subfertile couple with t(4;22)(q23;q11.2)

A couple was referred for cytogenetic examination due to idiopathic miscarriages. The proband proved to be a carrier of chromosomal translocation and her partner's karyotype was found to be normal. The karyotype of the proband is 46,XX,t(4;22)(q23;q11.2) and can be regarded as a reason of fertility problems in the investigated couple. The risk of further miscarriages is high, but the risk of a progeny with abnormal karyotype is rather low, as the progeny would probably have lethal imbalances.     

Partial duplication 14q/deletion 2q in two sibs due to t(2;14) (q37.1;q31.2) pat

Two siblings are described with duplication 14q/deletion 2q due to a paternal translocation (2;14) (q37.1;q31.2). The first one, a boy, born at term, lived 14 days. The second one, a female foetus, was born after induced labour when the anomaly was discovered by way of amniocentesis. They both had almost identical phenotypes. From a study of the literature it is inferred that a typical asymmetric head form, low set abnormal ears, micrognathia, long upper lip, rib anomalies, camptodactyly, long fingers and contractures are prominent features of the syndrome.     

A case of (13q;18q) translocation with proximal 13q monosomy

Summary A case of partial monosomy of the 13p terminal to 13q12, associated with a de novo 13/18 translocation, is reported. The symptoms appeared to be derived from both 18q- and partial monosomy 13, the latter giving rise to: high arched palate, epicanthus, antimongolian slant, small eye fissure, flat nasal bridge, hypoplastic helix, and large clitoris. Serum Ig-A and Ig-M levels were normal in our case.     

Sperm chromosome analysis of two men heterozygous for reciprocal translocations: t(1;9)(q22;q31) and t(16;19)(q11.1;q13.3).

Sperm chromosome complements were analysed in two men who were heterozygous carriers of reciprocal translocations. A total of 363 sperm were karyotyped after in vitro penetration of hamster oocytes, including 180 sperm from a male with a t(1;9)(q22;q31) and 183 from a male with a t(16;19)(q11.1;q13.3). All possible 2:2 and 3:1 meiotic segregations were observed for both translocations. The frequencies of alternate, adjacent 1, adjacent 2, and 3:1 segregations were 46%, 38%, 13%, and 4% for the t(1;9) and 40%, 28%, 31%, and 1% for the t(16;19), respectively. Within the alternate segregation group, the number of normal sperm was not significantly different from the number of sperm carrying a balanced form of the translocation for either of the translocations, as expected. There was no evidence for an interchromosomal effect of either translocation, since the frequencies of numerical abnormalities unrelated to the translocation were within the normal range observed in sperm from control donors. The percentage of sperm with an unbalanced form of the translocation was 54% for the t(1;9) and 61% for the t(16;19).     

Partial trisomy 4q: Two cases with a familial translocation t(4;18)(q27;q23)

Clinical and cytogenetic data of two related patients, both trisomic for the segment 4q27 to qter, are reported. Familial studies determined that the mothers of the two probands were carriers of the same balanced translocation between chromosomes 4 and 18. Altogether, two partial trisomies 4q, five balanced karyotypes, and one 45,X0 karyotype were found in the family. The 18 cases reported to date are reviewed with respect to the karyotype-phenotype correlation.     

Chromosome 4q;10q translocations; Comparison with different ethnic populations and FSHD patients

Background  

Facioscapulohumeral muscular dystrophy (FSHD) is an autosomal dominant disorder characterized by the weakness of facial, shoulder-girdle and upper arm muscles. Most patients with FSHD have fewer numbers of tandem repeated 3.3-kb KpnI units on chromosome 4q35. Chromosome 10q26 contains highly homologous KpnI repeats, and inter-chromosomal translocation has been reported.     

Trisomy 11 q (q23.1 - qter) through maternal translocation t(11;22) (q23.1;q11.1). A new case]

A 4-year-old boy with partial trisomy 11q resulting from malsegregation of a maternal translocation, t(11;22)(q23.1;q11.1), exhibits the following malformations: severe mental deficiency; growth retardation and hypotonia; brachycephaly with flattened occiput and forehead; facial dysmorphia; pre-auricular fistula. These features are in good agreement with the syndrome recently described for partial trisomy 11q. The translocation appears to be identical in that in three other families already reported.