Familial translocation 15-22. A possible cause for abortions in female carriers

Unbalanced translocation 46,XY,-15,+der(22)t(15;22)(q13;q11)pat: case report and review of the literature

We present a boy with a rare unbalanced translocation 46,XY,-15,+der(22),t(15;22)(q13;q11) pat. Previous reports of similar chromosome findings mention only the Prader-Willi phenotype. At birth, his manifestations included severe hypotonia and lethargy, (typical of deletion of 15pter----q13); hypertelorism, down-slanting small palpebral fissures, preauricular tags, long philtrum (typical of duplication of 22pter----q11); severe laryngotracheomalacia, and proximal implantation of the thumb. In a review of the literature on chromosome abnormalities involving duplication of 22q11 the associated clinical phenotype consists of mild mental retardation, microcephaly, hypotonia, hypertelorism, down-slanting palpebral fissures, a long philtrum, cleft or highly arched palate, and ear abnormalities. Preauricular pits or tags are common. Cardiovascular defects, renal and genital problems and dislocated hips are frequently present. Anal atresia and colobomata are mainly seen in cat-eye syndrome, the phenotype associated with idic 22q11. Our findings indicate that patients with unbalanced t(15;22) can have manifestations of the dup 22q11, in addition to the previously reported Prader-Willi phenotype, even if the duplicated segment is small.

Trisomy 22 in a newborn with multiple malformations

A case of complete trisomy 22 in a 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 mosaicism syndrome and Ullrich-Turner stigmata

Mosaic trisomy 22, ascertained in three unrelated patients, was found to be associated with body asymmetry and signs of the Ullrich-Turner syndrome including short stature, ptosis, webbed neck, nevi, cubitus valgus, dysplastic nails, malformed great vessels, and abnormal ovaries. These anomalies in trisomy 22 mosaicism have not been emphasized heretofore. In each of our patients, trisomy 22 mosaicism was found only in fibroblasts. In one patient, the trisomy resulted from a paternal first meiotic nondisjunction, and in the 46,XX cells, both chromosomes 22 were of paternal origin.

The aetiology of the cat eye syndrome reconsidered

The cat eye syndrome (CES), usually ascribed to the presence of a deleted supernumerary 22 chromosome, is characterised by a typical clinical picture including anal atresia, ocular coloboma, preauricular tags or sinuses, congenital heart defects, urinary tracts anomalies, and mental and physical retardation. An analysis of published reports revealed that of the 57 reported cases, only 21 showed the complete form, and 11 had a normal karyotype. Several observations question the existence of a trisomy 22:(1) the absence of any report in living subjects of trisomy 22 arising from an inherited Robertsonian translocation; (2) the recurrent abortions in carriers of Robertsonian translocations involving chromosome 22; and (3) the existence of a syndrome, showing the same clinical features as trisomy 22, which is irrefutably dependent on a trisomy of the distal region of the 11 long arm. On the basis of a comparison of the clinical features in full trisomy 13, partial 13 trisomies, 13 rings, 13 deletions, and CES the small marker present in this syndrome is considered to be a chromosome 13 with an interstitial deletion. An attempt to map this chromosome has been made.

Incomplete trisomy 22. III. Mosaic-trisomy 22 and the problem of full trisomy 22

A severely growth-retarded female newborn is described, who dies a few hours after birth. About half of the clones and metaphases from an amniotic fluid cell culture (set up at 35th week of gestation) and only 1/27 of the metaphases from a blood lymphocyte culture contained an additional No. 22 chromosome. Abnormal findings in the patient included a complex congenital heart defect, membranous anal atresia without fistula, distal limb hypoplasia, partial cutaneous syndactyly between second and third toes, and a left preauricular pit. On the basis of this case and other reports from the literature arguments for and against the existence of full human trisomy 22 are discussed. The conclusion seems likely, that full trisomy 22 usually presents a lethal condition in man, though at present an occasional survival cannot be excluded.

Trisomy 22 in a 20-year-old female

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.

Partial trisomy 22: a recognizable syndrome

A patient identified as being a partial trisomy 22 mosaic is presented. The presence of a translocation t(4;22) (pter;q12) is noted in the mother, sister and maternal aunt. Comparison is made with nine other reported cases of partial trisomy 22 confirmed by parental translocation. These suggest a definite syndrome, including mental retardation, congenital heart disease, skeletal anomalies, anti-mongoloid slant of the palpebral fissures, preauricular skin tags and low-set ears.