Ring-1 Chromosome and Microcephalic Dwarfism

A large deletion of chromosome no. 1 (46,XY,1?--).

“…1 of the type described in the present paper has, to the best of the author's knowledge, not been reported before. However, a ring-i chromosome has been reported in one instance (Gordon and Cooke, 1964). Ring chromosomes are formed when terminal deletions are followed by the joining together of the exposed ends.…”

The level of 6‐phosphogluconate dehydrogenase (6‐PGD) activity in a patient with a 1p terminal deletion suggests that the gene locus is not distal to sub‐band p36.3 on chromosome 1

“…Unfortunately, the likely loss of chromosomal material from 15q in each of these cases precludes definitive analysis of the phenotypic effects of the l p deletion. Similar confounding factors complicate case reports of several ring 1 chromosomes (which necessarily involved terminal deletions of lq as well as lp) which displayed growth failure with mental retardation (Kjessler et al 1978, Bobrow et al 1973, Wolf et al 1967, Gordon & Cooke 1964. Yunis et al (1981) reported on a 4-yearold patient with severe growth and mental retardation and multiple anomalies including enophthalmos and abnormal EEG.…”

Multiple congenital anomalies associated with a ring-D chromosome.

“…Ring chromosomes have been observed in group A (Gordon and Cooke, 1964), in group B (Rohde and Tompkins, 1965), in group C (Lindsten and Tillinger, 1962;Turner et al, 1962;Luers, Struck, and Nevinny-Stickel, 1963;Bain, Gauld, and Farquhar, 1965;Bishop et al, 1966), in group D (Bain and Gauld, 1963;Turner, 1963;Reisman, Darnell, and Murphy, 1965;Jacobsen, 1966;Gerald et al, 1967;Sparkes, Carrel, and Wright, 1967), in group E (Wang et al, 1962;Genest, Leclerc, and Auger, 1963;Lucas et al, 1963;Gropp, Jussen, and Ofteringer, 1964;Gripenberg, 1967), in group G (Lejeune et al, 1964;Hecht, Weleber, and Giblett, 1967), and when the group of origin could not be determined (Atkins, Sceery, and Keenan, 1966). They have also been reported in association with a specific disease (Di Grado, Mendes, and Schroeder, 1964), in tumours (Levan, 1956;Sandberg et al, 1967;Miles, 1967), and after radiation (Tough et al, 1960;Buckton et al, 1962).…”