Topic
Ring chromosome
About: Ring chromosome is a research topic. Over the lifetime, 1546 publications have been published within this topic receiving 31061 citations. The topic is also known as: supernumerary circular chromosome.
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TL;DR: A congenital chromosome abnormality was found in two unrelated children with acute lymphoblastic leukemia (ALL) and could be explained by different mechanisms: amplification of oncogenic determinants by gene duplication, and/or alteration of the effects of wildtype alleles through deletion or changes in position.
15 citations
Journal Article•
15 citations
TL;DR: It is indicated that a hemizygous state for the myelin protein gene may be related to the abnormal myelination in a Japanese boy with ring chromosome 18 in whom abnormalMyelination was observed on magnetic resonance imaging.
Abstract: We describe a Japanese boy with ring chromosome 18 in whom abnormal myelination was observed on magnetic resonance imaging. Cytogenetic investigation revealed 46, XY, r(18) (p11.2 q21.33). T 2- weighted magnetic resonance imaging scan of the brain demonstrated high signal intensity consistent with abnormal myelination. Microsatellite marker analysis of DNA demonstrated only one copy of the myelin basic protein gene, derived from the mother. The present case indicates that a hemizygous state for the myelin protein gene may be related to the abnormal myelination.
15 citations
TL;DR: A mentally retarded boy with a ring chromosome 22, where most of band q13 was deleted, is reported, and the fact that the leucocyte β‐galactosidase and a‐galactsidase B activities were normal is consistent with a gene dosage effect.
Abstract: A mentally retarded boy with a ring chromosome 22, where most of band q13 was deleted, is reported. The fact that the leucocyte beta-galactosidase and alpha-galactosidase B activities were normal, but the arylsulphatase A activity only half of the normal is consistent with a gene dosage effect and that the arylsulphatase A locus is located more distally, than the gene loci for the other two enzymes, in the deleted part of 22q13.
15 citations
TL;DR: A 15-month-old girl displayed the phenotype of fetal alcohol syndrome with short stature, preand postnatal dystrophy, microcephaly, psychomotor retardation and abnormal facial features, and a chromosomal analysis was performed.
Abstract: Sir: The diagnosis of the fetal alcohol syndrome is based on well-known, variable clinical signs and a history of excessive alcohol consumption during pregnancy. A 15-month-old girl displayed the phenotype of fetal alcohol syndrome with short stature, preand postnatal dystrophy, microcephaly, psychomotor retardation and abnormal facial features (Fig. 1). In addition, the child had a small ventricular septal defect and a haemangioma over the left eyebrow. The mother reported having consumed one bottle of wine at the time the unwanted pregnancy was noted but denied any alcohol intake thereafter. Since the mother seemed to be reliable and as there were no signs of prenatal infection or other causes of the retardation-multiple anomaly syndrome, a chromosomal analysis was performed. Chromosomal analysis was carried out on peripheral lymphocytes and cul-
15 citations