Moderate Down's syndrome in three siblings having partial trisomy 21q22.2→qter and therefore no SOD-1 excess

Summary Three mentally retarded siblings with moderate stigmata of Down's syndrome were found to have a partial trisomy 21q22.2qter resulting from a maternal translocation t(4q+;21q-). By the exclusion of any excess of SOD-1 in them, we can confirm the nonessentiality of the sub-band 21q22.1 and of the SOD-1 excess for most of the Down's syndrome stigmata including the mental retardation. However, the sub-band 21q22.1 in triplicate might be required for the completion of the full syndrome, as for example is shown by the incomplete dermatoglyphic pattern on the palms in the patients.     

De novo trisomy 4pter→q21

Summary Clinical and cytogenetic findings in an infant girl with multiple congenital anomalies, principally anophthalmia, are presented. The patient's karyotype was 47,XX, +del(4)(pterq21), the largest partial trisomy of chromosome 4 reported. The possible mechanism of the origin of this abnormality is discussed.To whom offprint requests should be sent     

“de novo” trisomy 1q32→1qter and monosomy 3p25→3pter

Summary The syndrome of familial lymphedema (type Meige) with distichiasis was observed in father and son. The association with uvula bifida and submucous cleft of the palate is described for the first time.     

Partial trisomy 13q21→qter de novo due to a recombinant chromosome rec(13)dup q

Summary A female is described who has a karyotype with an additional distal half of 13q in a recombinant rec(13)dup q chromosome. Since her parents have normal karyotypes, the origin of her karyotype is assumed to be a premeiotic pericentric inversion de novo with crossing-over within the inversion loop at meiosis. By means of various banding techniques, the breaks preceding the rearrangement could be located exactly. The joint between the duplicated segment and the satellites of the receptor chromosome is of special note. The phenotype of the patient stated at the age of 9 months and at the age of 71/2 years was found to be related to the segments involved in the partial trisomy. The clinical features were largely in accordance with previous case reports having an identical extent of the triplicated 13q segment.     

Partial trisomy of distal 8q derived from mother with mosaic 8q23.3→24.13 deletion,and relatively mild expression of trichorhinophalangeal syndrome I

Summary A 17-month-old girl with a partial trisomy of distal 8q derived from her mother, who has a mosaic 8q23.3q24.13 deletion, was studied. Both showed a relatively mild phenotype of trichorhinophalangeal syndrome I. The karyotype of the proposita was designated as: 46,XX,-8,+der(8),inv ins(8;8)(p23.1;q24.13q23.3)mat. Her phenotype was considered similar to that of her mother despite the trisomies of distal 8q. She seems to be the first example of a partial trisomy of distal 8q derived from a parent with an interstitial deletion of a distal 8q segment and trichorhinophalangeal syndrome I.     

Assignment of human ferritin genes to chromosomes 11 and 19q13.3→19qter

Summary Extracts of hamster-human and mouse-human hybrids, some with translocations involving chromosome 19, have been assayed for both human spleen ferritin (rich in L subunits) and human heart ferritin (rich in H subunits). Hybrid lines retaining part of the long arm of chromosome 19 including the region 19q13.319qter produced human L type ferritin. This confirms the previous assignment of the ferritin gene to chromosome 19 (Caskey et al. 1983). However, lines retaining chromosome 11 were found to contain human H type ferritin suggesting that the gene for the H subunit is on this chromosome. The presence of chromosome 6 was not necessary for the expression of either H or L type human ferritin. It thus seems unlikely that the gene for idiopathic haemochromatosis is a ferritin gene.     

Assignment of the gene for carboxypeptidase A to human chromosome 7q22→qter and to mouse chromosome 6

Summary A rat cDNA probe for preprocarboxypeptidase A was used to follow the segregation of the human gene for carboxypeptidase A (CPA) in 49 human x mouse somatic cell hybrids using Southern filter hybridization techniques. CPA was assigned to human chromosome 7q22qter. Similarly, the probe was used to follow the segregation of the mouse gene for carboxypeptidase A (Cpa) in 19 mouse x Chinese hamster somatic cell hybrids. Cpa was assigned to mouse chromosome 6. The gene for carboxypeptidase A forms part of a syntenic group that is conserved in man and mouse.Preliminary chromosomal assignments of carboxypeptidase A in man and mouse have been made in abstract (Honey et al. 1983a, b)     

Duplication of the segment q12.2→qter of chromosome 22 due to paternal inversion 22(p13q12.2)

Summary A 1730-g male infant, born at 37 weeks gestation, had multiple congenital anomalies, consisting of microcephaly, hypertelorism, bilateral cleft lip and palate, micrognathia, lowset ears, and cryptorchidism. Chromosome analysis showed a recombinant 22 derived from the paternal inversion (22) (p13q12.2). The proband's karyotype is 46,XY,rec(22),dup q,inv(22)(p13q12.2)pat, which has a duplication of q12.2qter. An identical recombinant has been reported in a female infant in Mexico whose mother was a carrier of the inversion. Similar congenital anomalies present in these two patients demonstrate the phenotype of duplication of the distal long arm 22. This report also documents the occurrence of an identical inversion in two apparently unrelated Mexican families.     

Partial trisomy of the short arm of chromosome 3 (3p25→3pter)

Summary Two profoundly mentally mentally retarded brothers with partial trisomy for the distal part of the short arm of chromosome 3 (3p253pter) are described. Their anomaly arose as a segregation product of a balanced t(3p-;18q+) translocation in the mother. Compared with the other cases of partial 3p trisomy reported up to now, the present patients display a similar craniofacial dysmorphism with hypertelorism, broad nasal tip, short upper lip with prominent philtrum, and a large mouth with down-turned corners. Other stigmata, such as a prominent, high forehead with frontal bossing and full cheeks, were present during childhood but progressively disappeared.     

Interstitial deletion of the long arm of chromosome 7 46,XX,del(7)(pter→q2200::q3200→qter)

Summary We present a boy with the karyotype 46,XY,r3 and a phenotype with psychomotor and growth retardation, craniofacial anomalies, syndactyly of the toes, and edema of the feet. The karyotypes and phenotypes of both parents are normal.     

Partial 3q duplication syndrome and assignment of D3S5 to 3q25–3q28

Summary We report a girl with a de novo duplication of the distal part of the long arm of chromosome 3 and review the literature. Our patient had the facial characteristics and many other anomalies of the partial 3q duplication syndrome. As a hitherto undescribed symptom in partial 3q trisomy syndrome, she had microphthalmia. The karyotype of this girl was interpreted as an inverse duplication of the terminal portion of chromosome 3: 46,XX,inv dup (3)(pter-q28::q28–q25::q28-qter). Quantitative hybridisation studies with 3p and 3q probes gave a consistent 32 ratio of the relative intensities of the q bands in relation to the p bands between patient and control. This confirmed the presence of a 3q duplication and delineated the location of D3S5 to 3q25–3q28.     

Transposition of 9q34 and 22 (q11→qter) regions has a specific role in chronic myelocytic leukemia

Summary Six cases are reported of variant Ph translocations found among 240 patients with Ph-positive CML. Five cases had a three-chromosome rearrangement involving, in addition to chromosomes 9 and 22, chromosomes 7, 4, 2(two), and 3 respectively, and one case had a two-chromosome rearrangement 22/5. A review of the literature revealed that three- and two-chromosome variant Ph translocations are observed with equal frequency. It is postulated that all variant translocations are indeed three-chromosome rearrangements, that the specific event for the formation of the Ph chromosome is the reciprocal translocation 9/22, and that the transposition of regions 9q34 and 22 (q11qter), plays a major role in the development of CML.     

The genes for growth hormone and chorionic somatomammotropin are on the long arm of human chromosome 17 in region q21→qter

Summary We used a cloned cDNA probe for human growth hormone and Southern blotting techniques to analyze DNA from a series of rodentxhuman somatic cell hybrids for the presence of growth hormone-related sequences. Our results provide evidence for the assignment of the genes for growth hormone and chorionic somatomammotropin as well as a growth hormone-like gene to human chromosome 17. Analysis of mousexhuman hybrid cells containing only part of the long arm of chromosome 17 enabled us to localize these genes to region 17q2117qter.     

Regional localization of the human genes for S-adenosylhomocysteine hydrolase (cen→q131) and adenosine deaminase (q131→qter) on chromosome 20

Summary The gene loci for S-adenosylhomocysteine hydrolase (AHCY) and adenosine deaminase (ADA), two enzymes with related metabolic functions, have both been assigned to human chromosome 20. We have used rodent-human somatic hybrids containing translocations involving human chromosome 20 to more precisely determine the relative locations of the AHCY and ADA loci. Our results assign the AHCY locus to the long arm of chromosome 20, in the region cenq131, and ADA to the region q131qter.     

Possible trisomy 1q25→1q32 in a malformed girl with a de novo insertion in 1q

Summary A newborn female is described who exhibited a characteristic facial dysmorphology including deep-set eyes, broad nasal bridge, small mouth, higharched and narrow palate, severely receding mandible and misshapen ears; constant flexion of the proximal interphalangeal joints, and short distal phalanges and nails of fingers; a congenital heart defect; marked muscular hypotonia, motor and growth retardation. She died at 4 months of age. Her karyotype revealed an additional band in 1q. Banding patterns and clinical picture suggest duplication of the segment 1q251q32.     

10q(q23→qter) duplication: GOTs,HK1, and other gene markers

Summary Gene marker analyses have been carried out in a patient with 10q(q23qter) duplication. The observed elevation of red cell glutamic oxaloacetic transaminase activity is compatible with earlier somatic cell hybridization studies that mapped the locus to this region. Hexokinase-1 activity in the red cells was normal, which is consistent with its prior assignment to the unaffected part of chromosome 10 (10pterq23).     

Assignment of the apolipoprotein A-I gene to 11q23 based on RFLP in a case with a partial deletion of chromosome 11, del(11)(q23.3→qter)

Summary The XmnI genotype at the apolipoprotein A-I locus was heterozygous in a boy with partial deletion of the long arm of chromosome 11, del(11)(q23.3qter). The apolipoprotein A-I gene, previously assigned to chromosome region 11q23q24, has been more specifically localized to 11q23 by excluding the region 11q24qter.