Cat eye syndrome. Partial trisomy 22 due to translocation in the mother

Association of Anterior Glottic Webs with Velocardiofacial Syndrome (Chromosome 22q11.2 Deletion)

OBJECTIVE: An association between anterior glottic webs and velocardiofacial syndrome (chromosome 22q11.2 deletion) has previously been noted in a number of case reports. Our objective was to determine if the presence of such webs warrants a high index of suspicion for this chromosome deletion.

STUDY DESIGN AND SETTING: This study was carried out in the Division of Pediatric Otolaryngology-Head and Neck Surgery at Cincinnati Children's Hospital Medical Center. Chromosome 22q11.2 deletion status was determined for all patients endoscopically diagnosed with anterior glottic webs between July 1998 and December 2000. Families of patients who tested positive for the deletion were referred to the Cincinnati Children's Division of Human Genetics for additional evaluation and counseling.

RESULTS: Eleven of 17 patients (65%) with anterior glottic webs were positive for chromosome 22q11.2 deletion. Of these 11 patients, 5 showed subtle clinical manifestations of velocardiofacial syndrome and underwent genetic testing due only to the presence of a web. All 11 patients were diagnosed with velocardiofacial syndrome.

CONCLUSION: We strongly recommend that all patients diagnosed with anterior glottic webs undergo fluorescence in situ hybridization evaluation for this chromosome deletion. (Otolaryngol Head Neck Surg 2004;130:415-7.)

11q trisomy detected by fluorescence in situ hybridization

A patient with psychomotor developmental delay, multiple minor anomalies, congenital heart disease and left inguinal hernia is reported. His karyotype was 45,X/46,X,+mar (3:37 cells), and the marker chromosome was identified as t(Y;11)(q12;q14?) using fluorescence in situ hybridization and fluorescent chromosome painting. He was diagnosed as mosaic for de novo 11q trisomy.

Ocular findings in CHARGE syndrome. Six case reports and a review

CHARGE syndrome is a group of nonrandomly occurring congenital anomalies which may present to the ophthalmologist, because coloboma is one of the major findings. In a series of 54 patients with ocular colobomata, 6 (11%) were found to meet the criteria for CHARGE syndrome. The mnemonic CHARGE stands for the major features of this syndrome: Coloboma, Heart defects, Atresia of the choanae, Retarded growth and development, Genital hypoplasia, and Ear anomalies and/or hearing loss. No specific etiology is known, but autosomal dominant, autosomal recessive, and X-linked recessive forms have been suggested by familial reports. The authors describe six patients with CHARGE syndrome, including the second reported case occurring in monozygotic twins. Other syndromes, chromosomal defects, and effects of teratogens may have similar clinical presentations. Though our prevalence may be skewed by our referral setting, the frequency of occurrence of this syndrome is certainly high enough that ophthalmologists should be familiar with it. Evaluation for associated defects should be carried out and referral for genetic evaluation undertaken when appropriate.

Translocation of c-sis protooncogene in peripheral neuroepithelioma

Molecular genetic analysis of the c-sis protooncogene was performed on two neuroepithelioma cell lines carrying a t(11;22)(q24;q12). The c-sis protooncogene was found by in situ hybridization to be translocated from its germline position on chromosome #22 to the derivative chromosome #11 in each cell line. However, it was not rearranged or amplified in either cell line examined. In addition, we did not detect c-sis transcripts in Northern blots of poly (A)+ RNA. This is similar to results found in Ewing's sarcoma, which carries a cytogenetically indistinguishable translocation from neuroepithelioma.

Sirenomelia and anencephaly in one of dizygotic twins

The combination of sirenomelia and anencephaly was observed in a stillborn dizygotic twin. A review of the literature revealed no other patients reported to have both conditions. Various explanations concerning the genesis of sirenomelia, and also the combination with anencephaly, are discussed.

Congenital heart disease in supernumerary der(22),t(11;22) syndrome

Congenital heart disease occurred in 62% of the reported cases of supernumerary der(22) syndrome. These were most commonly acyanotic lesions such as atrial septal defect, ventricular septal defect or patent ductus arteriosus. Heart disease did not, however, appear to be a major determinant of survival.

The spectrum of clinical features in CHARGE syndrome

Fifteen patients with CHARGE syndrome are described, nine sporadic and six familial. A recognizable pattern of malformations is present which appears to constitute a syndrome rather than a non-random association. In addition to acronymic features of Coloboma, Heart disease, Atresia of the choanae, Retarded growth and development, Genital hypoplasia, and Ear anomalies, other important diagnostic features include facial paralysis and feeding problems suggestive of velopharyngeal incompetency. A square facial appearance with asymmetry and malar flattening is characteristic, and long philtrum or prominent nasal columella may be present. Characteristic external ear anomalies and a 'wedge'-shaped audiogram may be unique to this syndrome. Short stature and hypogonadism with genital hypoplasia is pituitary or possibly hypothalamic in origin. Each feature varies from normal to severe involvement including mental function, and no single feature appears to be necessary for diagnosis.

Balanced reciprocal translocations: risk factors for aneuploid segregant viability

Reciprocal translocations were studied in two groups of balanced carrier couples: 202 had 210 translocation aneuploid between (LB) infants, and 95 couples had repetitive abortions (AB) without liveborn aneuploids. The observed translocation aneuploidies in the LB group were compared to predicted potential aneuploidies in AB by frequency of chromosome involvement, meiotic segregation mode, and mean trisomic, monosomic and combined genomic imbalances. Qualitative and quantitative differences identified genomic regions and chromosomes possibly vital for in utero survivability. LB aneuploidies indicate non-random chromosome involvement, selection of least detrimental segregants and segments, and predominant transmission from maternal balanced carriers (especially in 3:1 tertiary segregation, 93.5%). For an individual with a balanced reciprocal translocation and untested reproductive capability, an approach is given for predicting whether a translocation aneuploid conceptus will be liveborn or aborted.

Cat-eye syndrome with unusual marker chromosome probably not chromosome 22

An unusual supernumerary chromosome with a single satellite on the long arm was found in a child with manifestations of the cat-eye syndrome including apparently low-set and malformed ears, preauricular tags, micrognathia, and imperforate anus. Although G-banding suggested that this extra material was chromosome 22, this was not confirmed by several other banding techniques. After examination of the parents' chromosomes, the nature and origin of this extra chromosome remains obscure. We conclude that patients previously diagnosed as having "partial trisomy 22" with incomplete cat-eye syndrome may have a different chromosome constitution when studied by various banding techniques.

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.

A bisatellited marker chromosome in an infant with the caudal regression anomalad

An infant with the caudal regression anomalad is described. Karyotypic analysis revealed mosaicism for a bisatellited microchromosome. Using banding techniques, an attempt was made to further identify the marker chromosome. It is suggested that a causal relationship exists between the cytogenetic findings and the clinical observations.

Incomplete trisomy 22. I. Familial 11/22 translocation with 3:1 meiotic disjunction. Delineation of a common clinical picture and report of nine new cases from six families

A syndrome due to 3:1 meiotic segregation of balanced 11/22 translocation is defined from nine personally observed patients and 22 cases from the literature with apparently the same aberration. Frequent findings include a characteristic face with deep-set eyes, flat nose, prominent upper lip, receding mandible and preauricular pits or tags, male genital hypoplasia, anal atresia or other anomalies of the anus, cleft palate, and congenital heart defect. Less frequent are severe reduction of the auricles, an additional pair of ribs, and hypoplasia of the diaphragm. Perinatal mortality is high. Growth is usually and psychomotor development is invariably and severely delayed. Balanced 11/22 translocations are apparently disproportionally frequent; as the balanced rearrangement is not easy to detect, it is important to be aware of it at the family investigation of cases with extra chromosomes similar to a No. 22 or 22q-. The unbalanced products are most probably trisomic for both a segment of 22 (22q-) and a distal segment of 11q; the exact determination of the breakpoints is not possible at present due to the similar banding characteristics of the two segments involved in the translocation.

Brief Clinical Report: coloboma hypospadias

We report a five-year-old boy with bilateral ocular coloboma, hypertelorism, hypospadias, and mental retardation. The father has hypertelorism and a deceased sibling had unilateral iris coloboma. This observation my represent 1) the BBB syndrome with coincidentally segregating coloboma; 2) discovery of coloboma as a new but rare component manifestation of the BBB syndrome; or 3) a new autosomal dominant pleiotropic syndrome.

Complex chromosomal rearrangement leading to partial trisomy 22

We have examined a boy with a peculiar facial appearance and mental retardation. Cytogenetic studies showed 47,XY, monosomy 22, two marker chromosomes, M1 and M2. The karotype is interpreted as functionally partial trisomy 22. Chromosome analyses of both parents and three sibs were normal.

Site-specific reciprocal translocation, t(11;22) (q23;q11), in several unrelated families with 3:1 meiotic disjunction

We have studied 32 unrelated families with a site-specific reciprocal translocation between chromosomes 11 and 22 [t(11;22) (q23;q11)]. In translocation heterozygotes 3:1 meiotic segregation occurs and results in abnormal progeny who carry the der(22) as a supernumerary chromosome. Phenotypic findings consistent with 47,XX (or XY), +der(22), t(11;22) include mental retardation, preauricular skin tag and/or sinus, ear anomaly, palate anomaly, micrognathia, congenital heart disease, and genital anomalies in males. The frequency of abortions among offspring of male and female heterozygotes is increased. Segregation analysis shows that the risk of unbalanced offspring to be born to female heterozygotes may be as high as 10%, and that there may be a significant risk to male heterozygotes as well. The overall carrier frequency among progeny of 11;22 translocation carriers is 70.6%. The occurrence of multiple 11;22 translocation events is supported by de novo occurrence of translocation, familial heteromorphic variants of the der(22), and varied racial and ethnic backgrounds of the families. To our knowledge, with the exclusion of centric fusion translocations, this represents the only example of nonrandom exchange in a constitutional chromosomal rearrangement.

A chromosome survey of a hospital for the mentally subnormal

A cytogenetic survey of 756 resident, but otherwise unselected, mentally retarded patients in a Scottish hospital is reported. The karyotypes of all patients were examined using orcein-stained cells, and those found to be abnormal, other than those with standard trisomy 21, were further investigated using a banding technique. A total of 103 patients were found to have an abnormal chromosome complement, of whom 91 had Down's syndrome (including six with translocations), six had some other autosomal abnormality, and six had an abnormality of the sex chromosome complement, including two with an XXYY complement. Details of the clinical and cytogenetic features are presented.

The problem of partial trisomy 22 reconsidered

A patient with partial trisomy 22(PT22) is presented. Inheritance is presumed to be due to secondary nondisjunction in her mother, who has a balanced translocation t(11;22)(q25;q13). The problem of the phenotypic heterogeneity observed with this chromosome change is discussed.