Developmental Abnormalities Associated with a Ring Chromosome 6

Ring chromosome instability evaluation in six patients with autosomal rings

“…Some researchers found higher frequencies of monosomic cells without the ring chromosomes in fibroblast compared to lymphocyte cultures (Sparkes et al, 1967;Moore et al, 1973;Palmer et al, 1977;Peeden et al, 1983), while others found no significant differences between the two tissues (Valente et al, 1977;Ledbetter et al, 1980;Manouvrier-Hanu et al, 1988). Ledbetter et al (1980), however, found ring chromosomes 15 with an abnormal morphology in 9% of metaphase cells from lymphocyte cultures and in 20 and 24% of cells from fibroblast cultures in the third and tenth subculture, respectively, although it was not possible to know if these cells were formed de novo or were perpetuated in a clonal manner.…”

A ring C7 chromosome in a mentally and physically retarded male with various somatic abnormalities

“…Whereas those findings are marked also in several other types of chromosome abnormality syndromes and not characteristic features of the individuals with the ring C chromosome. Recently, with banding techniques, it has been possible to identify the affected chromosome, and three cases with ring C6 chromosome (Moore et al, 1973 ;Van den Berghe et al, 1974;Fried et al, 1975), two with ring C7 (Zackai and Breg, 1973) and three with ring C9 (Jacobsen et al, 1973;Fraisse et al, 1974;Zdansky et al, 1975) have been reported. Clinical findings of the three individuals with ring 7 chromosome, two reported by Zackai and Breg and the present case, were markedly different, and the only findings in common in these three are microcephaly, short stature and hemangioma on the forehead.…”

“…Among them 19 cases of congenital abnormalities possibly associated with ring C chromosomes have been reported (Turner et al, 1962;Smith-White et al, 1963;Atkins et al, 1966;Butler et al, 1967;Wurster et al, 1969;Bueno et al, 1969;Kistenmacher and Punnett, 1970;Gacs et al, 1970;Therkelsen et al, 1971;de Chieri et al, 1972;Moore et al, 1973;Zackai and Breg, 1973;Jacobsen et al, 1973;Van den Berghe et al, 1974;Fraisse et al, 1974;Fried et al, 1975;Zdansky et al, 1975). Above all, in recent 8 cases the specific chromosomes from which rings were formed have been precisely identified either by Giemsabanding or fluorescence techniques.…”

Dirençli epilepsi olgusunda mozaik ring kromozom 6 ve klinik önemi

“…Phenotype and genotype may show difference, since the amount of substance deleted at the ends varies from patient to patient. (3,4). Ring chromosome 6 was defined by Moore et la.…”

“…Afterwards, cases from different areas have been reported occasionally. These diseases reported have generally been diagnosed postnatally, but there are also patients who have been diagnosed prenatally (3,4,5,6). Chilren with ring chromosome 6 who have been reported until the present time in the literature have been observed to display a wide clinical spectrum ranging from normal intelligence level to neurologic and dysmorphic findings including epilepsy, hydrocephaly, microcephaly and mental retardation (5,6).…”