Trisomy 22.

The existence of a trisomy 22 has been definitely established by newer methods of karyotype analysis which permit distinction between the acrocentric chromosomes of group G. Trisomy 22 is much rarer than trisomy 21. This report presents presumptive evidence that the cat eye syndrome (CES), the so-called "trisomy 22" (T22), the intermediate cases (IM) with cardinal symptoms of CES and T22, and some cases of mental retardation with rather unspecific symptoms are variants of the same disease entity. For T22, CES and one abortive case the extra chromosome was clearly identified as number 22 chromosome with or without partial deletion of the long arm. An interesting and presently not fully understood feature of trisomy 22 is its frequent familial incidence.     

Trisomy 22 in a 20-year-old female

Summary Trisomy 22 was confirmed in a 20-year-old ambulatory female. Growth and mental retardation plus various dysmorphic features of this syndrome are described and compared with a previous survey. Several interesting unreported findings such as sexual immaturity and gait are discussed in regard to the 22 trisomy syndrome.Gracewood State School and Hospital     

Trisomy 22 in a newborn with multiple malformations

Summary A case of complete trisomy 22 in live-born female child with multiple malformations is reported. The karyotype of the index patient had 46 chromosomes, with one chromosome 22 missing and one supranumerary metacentric chromosome. Different banding methods and in situ hybridization revealed that the extra chromosome consists of the long arms and a part of the short arms of two chromosomes 22. Our report supplies further proof that a fetus with complete trisomy 22 can occasionally survive to term, but the condition is not compatible with life over a long period.     

Trisomy 22 with holoprosencephaly: a clinicopathologic study

Trisomy 22 (47, XY, +22) was found at 17 weeks gestation in one fetus of a twin gestation. The karyotypes of both parents and of the other twin were normal. Abnormal prenatal findings included maternal pre-eclampsia, fetal growth retardation, and progressive intracranial sonolucency of the trisomic fetus. Delivery by cesarean section at 36 weeks gestation yielded a normal healthy female weighing 2,822 grams and a markedly macerated dysmorphic male weighing 642 grams. Holoprosencephaly was found in the trisomic fetus, an unusual feature in trisomy 22. Additional findings in this case are compared to other findings in the literature.     

A Case of Trisomy 22 in a Live Hereford Calf

A case of the rare genetic trisomy 22 in a live calf is described. The calf had low blood thyroxine level and low growth rate. It had several defects including brachygnathia superior, strabismus convergence, aortal cusp insufficiency and hypertrophy of clitoris. Chromosome analysis was performed on cultured blood lymphocytes and fibroblast cells. In all counted metaphases 61 chromosomes were present. The extra chromosome was identified as a chromosome 22 by R-banding. The defects of the calf have similarities with cases of partial trisomy 3p25-pter in human. This section of the human chromosome 3 corresponds to sections of cattle chromosome 22.     

Trisomy 8

Summary Trisomy 8, in mosaic or non-mosaic form is an extremely rare chromosomal condition in man. Liveborn subjects usually present with mental retardation, bone and joint anomalies and a variety of other physical anomalies. The mental retardation associated with the condition is, however, usually moderate compared to that found in other viable human autosomal trisomic conditions. The present report describes a trisomy 8 mosaic male subject with normal IQ and near-normal phenotype, ascertained through infertility. Chromosome studies on peripheral blood lymphocytes reveal a pure trisomy 8 constitution; cultured skin fibroblasts show 46,XY/47,XY+8 mosaicism. At meiosis, the extra No. 8 chromosome is missing from the germ line. The testicular histology indicates a germ cell maturation arrest in many spermatocytes and the patient is severely oligospermic. Biochemical studies to assay levels of glutathione reductase, a red cell enzyme, the gene for which resides in chromosome 8, show increased levels in the trisomy 8 patient compared with controls.     

Trisomy 18q

Summary A 2-month-old male infant with partial trisomy 18, 46,XY,der(4),t(4;18)(q35;q21.1)mat, was presented. Except for atypical facies, he had many of the significant signs of full trisomy 18. Phenotype-karyotype correlations based on the data of our case and those from the literature were discussed. Major features of trisomy 18, such as congenital heart disease, early death, and external malformations, appear to be consistently related to the trisomic state of 18q21. Characteristic congenital heart diseases in trisomy 18 were polyvalvular disease in 100%, membranous ventricular septal defect, patent ductus arteriosus, and high take-off of the right coronary ostium. Pathology of the heart did not differ between full and partial 18-trisomy cases.     

Trisomy iop.

A stillborn male fetus having a trisomy of the short arm of chromosome No 10 is described. The father is a carrier of the reciprocal translocation 46XY,t(10;21) (10pter leads to 10p11::21p11 leads to 21qter). The clinical picture included growth retardation, bilateral cleft lip and palate, micrognathia, short neck, microphalus and bilateral clubbed feet. The long bones were markedly thinned with spontaneous fractures. Autopsy findings included pulmonary hypoplasia and renal dysplasia. Previous reports of trisomy 10 and trisomy of the short arm of chromosome 10 are discussed.     

Trisomy 21 Down syndrome

Summary The lymphocyte chromosomes of trisomy 21 Down syndrome patients and their parents in a random series of 374 families were analyzed, the objective being the identification of parental mosaicism. The numbers of parents in whom at least two trisomy 21 cells were detected were seven mothers and three fathers, a frequency of 2.7% of families. Confirmation of mosaicism was by identification of parental transmission of the extra chromosome to the progeny, by repeat chromosome analysis, and/or by the presence of more than one affected child. If to these are added six others in whom only one trisomic cell was detected, but with no other supporting evidence, the frequency could be as high as 4.3%. Differences in parental age at the birth of Down syndrome progeny may be accounted for by differences in frequencies of mosaicism in germ cells and somatic tissue. Mosaicism was found more frequently in the mothers than in the fathers, but more data are required for confirmation of a real difference.     

Trisomy 21 Down syndrome

Summary In a series of 374 families with Down syndrome progeny, structural chromosome rearrangements were detected in the parents of six children with regular trisomy. The aberrations were reciprocal translocations and inversions. In all three informative families, the parent who transmitted the extra chromosome was not the one with the structural rearrangement. Among the three non-informative families there was one in which both parents carried different reciprocal translocations. In two other families a chromosome aberration was detected: a triple X mother and a father with a Philadelphia chromosome. Omitting the four parents with possible biased asccrtainment, 0.4% had a chromosome rearrangement. When the parents with constitutional chromosome aberrations and those with mosaicism, described previously, are combined, the frequency of chromosomally abnormal parents lies between 1.9% and 3.2%. When correlated with parental transmission of the extra chromosome, mosaicism rather than structural rearrangements appears to be of ctiologic significance.     

Trisomy 19 q.

Two sibs with trisomy for the long arm of chromosome 19 are reported. The common features included flat facial profile with microcephaly, hypertelorism, ptosis, prominence of the glabella, small nose with anteverted nostrils and a characteristic fish-shaped mouth. In addition congenital heart disease, physical retardation and seizures were seen in both sibs. That tristomy 19q can be suspected clinically is emphasized.     

Trisomy 8 mosaicism syndrome

Authors present the case of a 15-year-old boy assessed for Marfan syndrome for many years. The child was treated because of skeletal defects, mild mental deficiency and dysmorphic features of face. Chromosomal analysis showed a trisomy 8 mosaicism.     

Trisomy 12p syndrome

Summary The first case of trisomy of probable 12p mosaicism originated de novo is presented. Comparison of the clinical findings of this patient with those of previously described cases of 12p trisomy derived from translocated chromosomes indicates that the symptoms of 12p trisomy are: (1) normal birth weight and physical development, (2) severe psychomotor retardation and generalized hypotonia, (3) peculiarly round face with prominent cheeks, hypertelorism, epicanthus, broad, flat nasal bridge, short nose with anteverted nostrils, large philtrum, broad, prominent lower lip, and (4) poly(syn)dactyly of feet.     

Trisomy 13 in the fetus

A significant number of fetuses with trisomy 13 are spontaneously or voluntarily lost before birth; however, very few such fetuses have been systemically autopsied. In the present study, ten trisomy 13 fetuses of 130-305 mm in crown-rump length, estimated gestational age from 108 days to 239 days, were examined following either karyotype or ultrasonographic diagnosis and voluntary termination. Mean maternal age was 35.1 years. The spectrum of anatomical features was similar to that observed in neonates or older infants with trisomy 13, namely, holoprosencephaly, cyclopia, microphthalmia, cleft palate and lip, cardiac defect, polydactyly, and cystic kidney. Kidney weights were significantly increased above normal in eight of nine fetuses. Histologically, the cortex of these kidneys showed increased mitotic activity and blastemic appearance, which extended deep into the medullary areas. The weights and histology of other organs were normal except for slight increases in spleen weight.