Richard L. Neu

A partial trisomy of chromosome 1 in a family with a t(1q-;4q+) translocation.

A female infant with approximately one‐third of the terminal portion of the 1q chromosome arm attached to the end of a 4q arm (46,XX,4q+) is described. The propositas mother, maternal grandfather and uncle are balanced translocation carriers 46,XX or XY,t(1q‐;4qf). The clinical findings were: elfin‐like facies, low set ears with large pinnae, and numerous cardiac anomalies. The proposita expired at eleven weeks of age.

Inclusion of satellites in an 18/21 translocation chromosome shown by ammonical-silver staining (sat-banding) in case of partial trisomy 18.

A male infant with a partial trisomy 18 and a 46,XY, --21, t(18;21)(18qter replaced by 18q12::21 p13 replaced by 21 qter) chromosome complement is described. The translocation chromosome is of special interest because it includes the satellites of chromosome 21. This was shown by differential satellite staining with the ammoniacal-silver technique.

EFFECTS OF ANTIBIOTICS ON CHROMOSOMES OF CULTURED HUMAN LEUCOCYTES.

PENICILLIN and streptomycin have been commonly added to growth media used in the culture of human leucocytes for cytogenetic analysis. Since the literature on human cytogenetics is increasing rapidly, largely through the use of these techniques, it seemed appropriate to examine any possible cytological effects of antibiotics per se on cultured human leucocyte chromosomes or on the mitotic index.

Trisomy C mosaicism in a seven month old girl

A female infant, first seen at age 7 months and again at 1 3/12 years, exhibited the following physical findings: low birth weight at full term; mental and growth retardation; brachycephaly; micrognathia; high arched palate; low set, slanted malformed pinnae; scant medial eyebrow hair; small, short nose with prominent skin folds over the nasal bridge; short neck; both hands were hypoplastic between thumb and index finger; a tendency to hold thumbs in pronation; abnormal dermatoglyphics; rocker-bottom feet; big toes kept in dorsi-flexed position; mottled skin; hypoplastic clitoris and labia minora.Cytogenetic studies on the patient revealed that 83% of the karyotyped peripheral leucocytes had 46 chromosomes and 17% had 47 chromosomes. Metaphases with 46 chromosomes exhibited the normal female complement. Metaphases with a count of 47 consistently had an extra chromosome in the C group. A labelled metaphase with 47 chromosomes showed only 1 late-replicating chromosome. The sex chromatin count was positive (30%) and no buccal cells with more than one sex chromatin body were observed.

Arborizing amniotic polyps in triploid conceptuses: A diagnostic anatomic lesion?

Abstract Characteristic structural abnormalities were found in an aborted human triploid/diploid conceptus and in 2 triploid human conceptuses. Arborizing amniotic polyps were present in each of the 3 specimens. The cell constitution of the polyps was found to be partially composed of mononuclear giant cells. There was hydatidiform degeneration of the chorionic villi in each specimen, and, in the triploid/diploid mosaic specimen and one of the triploid specimens, thick-walled chorionic cysts were present. No anomaly could be detected in either of the 2 triploid embryos which were recovered. Death and ultimate abortion of triploid embryos might result from abnormalities of the placenta and fetal membranes rather than from a lethal defect in the embryo proper.

Segregation of a t(14q22q) chromosome in a large kindred

A large kindred is reported in which 21 members are balanced t(14q22q) carriers. The components of the translocation were identified by autoradiography and G‐banding. With the exception of the index case, who was retarded, all of the carriers were phenotypically normal. The segregation pattern of the translocation chromosome was determined in two complete generations. All eight of the progeny in one generation were balanced carriers, and the carrier father of this generation may have been homozygous for the t(14q22q) chromosome. Segregation in the next generation was closer to the expected 1:1 ratio of carrier to non‐carrier, the ratio being 11:13.

XXXXY syndrome in a phenotypic male infant with associated cardiac abnormalities

SummaryA boy with 49,XXXXY karyotype is described with only mild mental retardation at 18 months. Physical abnormalities included patent ductus arteriosus, undescended testes, small penis, bilateral epicanthal folds, and incurved 5th digits with small middle phalanges. Literature review showed 7 previous cases of XXXXY patients with congenital heart disease. 23% of buccal cells showed 1 sex chromatin body; 26% showed 2 and 11% 3. Autoradiography demonstrated 3 heavily labelled X chromosomes. The heteropyknotic behavior of X Chromosomes in excess of one may provide some measure of protection against excessive numbers of X chromosomes, bence the relatively normal development of some XXXXY patients.

A 46,XX,t(Cp+;Cq-) translocation in a girl with multiple congenital anomalies and in her phenotypically normal father 46,XY,t(Cq+;Cq-).

It is clear that the detection of a chromosome aberration does not necessarily correlate with the presence of obvious physical or mental defects. For example, t(GqGq) or t(DqGq) balanced translocations may be found in phenotypically normal parents whose progeny have Downs syndrome. The present report described a balanced translocation involving the C group in father and daughter. The father is phenotypically normal, but the child has multiple anomalies.

48,XY,21+, mar+mat: a case of trisomy 21 associated with an inherited small marker chromosome.

A patient with Downs syndrome whose karyotype included a t(GqGq) translocation chromosome and a fragment has been reported by Penrose, Ellis, and Delhanty (1960). Subsequently, den Dulk et al. (1966) reviewed six patients with chromosome fragments associated with clinical abnormalities. None of these latter cases, however, had clinical pictures compatible with any of the established trisomies, such as those reported by Vislie et al. (1962), Fr0land, Holst, and Terslev (1963), and Dekaban and Zelson (1968), as well as others. This communication describes a case of trisomy 21 associated with an inherited marker chromosome.

A t(5p-;21q+) translocation in a family with Down syndrome

A mother and daughter carrying a t(5;21)(p13;q22) chromosome were discovered after they had contacted us for genetic counseling. They were concerned because of two cases of Down syndrome in their family. Four of the mothers eight pregnancies had resulted in miscarriages; the chromosome complements of the abortuses is not known. Evidence was found indicating that individuals carrying a structurally altered chromosome 21 have an increased risk of bearing a child with Down syndrome.