Transmission of ring chromosome 18 46,XX/46,XX,r(18) mosaicism in a mother and ring chromosome 18 syndrome in her son.

Inheritance of ring chromosomes is reported infrequently. The authors report on a phenotypically and mentally normal mother with ring chromosome 18 mosaic with a normal cell line and her polymalformed son with non-mosaic 46,XY,r(18) karyotype.     

Deletion of the long arm of chromosome 4 [46,XX,del(4)(q31)] in a patient with congenital anomalies.

A girl with congenital malformations and del 4(q31), identified by QFQ- and RFA- techniques, is described. The clinical findings are compared with the four cases of 4q- of the literature. Evident variability of the clinical features and the small number of cases of 4q- does not allow the delineation of a clinical syndrome.     

Rare case of mosaicism for chromosome 18, karyotype: 46, XX, del(18) (p11)/46, XX, i(18q)

Rare mosaicism of chromosome No 18 is described. The proposita is 5.5 years old and has two cell clones: 50% of cells are monosomic for 18p and 50% have isochromosome i18q. The ratio of these clones (1:1) is found to be similar at the age of the proposita 2.5 and 5.5 years. The proposita has some phenotypic characters of both 18p- (ptosis, epicanthus, deformed carious teeth, falled back sternum etc.) and trisomy 18q (contraction of external auditory meatus, femur luxatus congenitus etc.) syndromes. A possible mechanism for the origin of such a mosaicism is discussed.     

Partial monosomy of the long arm of chromosome 16 in a malformed newborn: Karyotype 46,XX,del(16)(q21)

Summary A polymalformed newborn with partial monosomy for the long arm of chromosome 16 is presented. Karyotype 46,XX,del(16)(q21).     

Interstitial deletion of the long arm of chromosome 2 in a polymalformed newborn-karyotype: 46,XX,del(2)(q21;q24)

Summary This report describes a polymalformed female newborn presenting an interstitial deletion of the long arms of chromosome 2. Karyotype: 46,XX,del(2)(q21 q24).     

Deletion mapping of DNA segments from the Y chromosome long arm and their analysis in an XX male

Twelve DNA segments have been localized to the long arm of the Y chromosome and were assigned to three intervals by deletion mapping. Of these segments, six were from distal Yq11.23, which is supposed to contain a spermatogenesis locus. The physical mapping information was used to analyze an XX male who is positive for DNA sequences both from distal Yp and from Yq. Two of the twelve sequences from Yq (Y-198 and Y-253) were detected in this patient along with two of six short-arm segments tested. Long-range physical mapping placed Y-198 and Y-253 on a common 1100-kb BssHII fragment. In this patient, the long-arm sequences were assigned to distal Xp by in situ hybridization. The data suggest that this XX male derived from an unequal interchange between an X and an inverted Y chromosome presumed to have been present in the patient's father.     

Terminal deletion of the long arm of chromosome 4. Report of a case of 46, XY, del(4)(q31) and review of 4q- syndrome

Using Q banding technique we recently identified a terminal deletion of the distal segment of the long arm of chromosome 4 in a male infant with multiple long arm of chromosome 4 in a male infant with multiple congenital anomalies. The breakpoint is at 4q31. The infant had hypertelorism, epicanthal folds, depressed nasal bridge, short nasal septum with upturned nose, bilateral open cleft lip and palate, retro- and micrognathia, low set, malformed ear, short neck, distally placed nipples, a sacral dimple, hypospadias, dysplastic nails, overriding toes, simian creases, patterns on interdigital and hypothenar areas, hypoplasia of gallbladder, and cardiac defects consisting of tricuspid atresia, left sided vena cava and anomalous aortic arch. This case is compared to the eight previously reported 4q- cases.     

Partial deletion of the long arm of chromosome 18

Summary A female infant with mental retardation and multiple somatic anomalies is described. The karyological analysis disclosed the partial deletion of the long arm of chromosome 18 in cells of probands peripheral blood culture. Repeated investigations of probands mothers peripheral blood cultures disclosed the presence of various chromosomal aberrations in 25–70% of cells.