Interstitial deletion of chromosome 1 [del(1)(q25q32)] in an infant with prune belly sequence.

Relatively few cases of deletion 1q have been reported. These cases have been divided into three groups according to assigned breakpoints. They include proximal interstitial, intermediate interstitial, and terminal deletions. We present a male infant with an interstitial deletion of 1q with breakpoints determined by GTG banding as q25 and q32. Comparison with similar case reports suggests common physical features which include microcephaly, growth retardation, developmental delay, clinodactyly, and genital anomalies in affected males. However, no characteristic phenotypic appearance is definable. The infant also presented with prune belly sequence (PBS) with Potter facies. Fetal ascites, as noted in this case on prenatal ultrasound, appears to be an early factor in the pathogenesis of PBS. Therefore, detection of fetal ascites should suggest the presence of the PBS association and the need for more extensive prenatal evaluation.

A de novo 3p;8p unbalanced translocation resulting in partial dup(3p) and partial del(8p).

We present the first case of a de novo translocation resulting in dup(3p). Giemsa banding studies tentatively identified the source of the extra genetic material as 3p. Clinical findings were compatible with those previously reported in dup(3p) patients, further defining this cytogenetic anomaly as a distinct, clinically identifiable syndrome.

An additional case of Smith-Lemli-Opitz syndrome in a 46,XY infant with female external genitalia.

Ambiguity of the external genitalia has been frequently documented in male patients classified as the Smith-Lemli-Opitz (SLO) syndrome. Four previous case reports suggest that in extreme cases of the SLO syndrome there may be complete lack of development of the male external genitalia even in the presence of a normal male 46,XY karyotype. We present an additional case of a phenotypically female infant with dysmorphic features compatible with SLO syndrome and a 46,XY chromosome complement.

Partial trisomy 6p and partial trisomy 22 resulting from 3:1 meiotic disjunction of maternal (6p;22q) translocation.

A male infant, partially trisomic for a small segment of chromosomes 6 and 22 resulting from a maternal translocation, is described. Comparison of the phenotypic features of the proband with those noted in partial 6p and partial 22 trisomies revealed some common features found in both chromosome anomalies but especially reinforced those features thought to be characteristic of 6p trisomy syndrome.

Paternal Robertsonian translocation t(13q;14q) and maternal reciprocal translocation t(7p;13q) in a couple with repeated fetal loss.

Marriages involving partners both of whom have abnormal karyotypes are rare and are usually ascertained because of a history of infertility, repeated abortions, or the birth of a balanced translocation carrier or chromosomally abnormal offspring. Abnormalities which have been noted include sex chromosome aberrations in both parents or a sex chromosome abnormality in one parent and an autosomal abnormality in the other. Four papers have reported balanced reciprocal autosomal translocations in both parents, two couples representing a first cousin marriage. We present a case of a paternal 13;14 Robertsonian translocation and a maternal (7p;13q) reciprocal translocation in a couple with repeated fetal loss.

Tetraploidy: a report of three live-born infants.

We present three live-born infants with tetraploidy and compare them with two previously reported live-born infants with the same genetic defect. Common anomalies noted included microcephaly; a prominent, narrow forehead; microphthalmia/anophthalmia; cleft palate; orthopedic anomalies; genital ambiguity; and abnormalities of the central nervous system, including pituitary hypoplasia. Together these constitute a rather characteristic phenotype. An error in cytoplasmic cleavage is theorized to be a mechanism for the chromosome anomaly and is supported by the presence of parental polymorphisms in one of our cases; however, the presence of a small percentage of tetraploid cells in the leukocytes and skin fibroblasts of this patient's mother does not exclude maternal mosaicism as the basis for polyploidy in certain instances.

An unbalanced (6q;13q) translocation in a male with clinical features of Ehlers-Danlos type II syndrome.

Ehlers-Danlos syndrome has been divided into several different types according to the variety and severity of clinical manifestations, and may follow autosomal dominant, autosomal recessive, or X linked patterns of inheritance. Only rarely have chromosome anomalies been seen in patients manifesting phenotypic features of the syndrome and most are considered insignificant. However, one case report involved a balanced t(9;17)(q34;q11) in a female with the clinical features of Ehlers-Danlos type I and IV syndromes and, as noted by McKusick: "It is possible, furthermore, that certain very rare syndromes that are transmitted in a Mendelian manner are the result of small chromosome aberrations, such as deletion or inversion, affecting the action of several genes". We present a 14 year old male with features of Ehlers-Danlos type II syndrome and an unbalanced (6q;13q) translocation.