Trisomy 14 mosaicism is a rare chromosomal abnormality with distinct and recognizable clinical features. We report a patient with presumed retinal dystrophy having diffuse retinal pigment epithelial abnormalities, which has not been previously reported in association with trisomy 14. This case expands the clinical spectrum of this rare entity.

Ambiguous genitalia, known to be associated with sex chromosome disorders, may also be seen with autosomal chromosome anomalies. Herein, we report a case with ambiguous genitalia and ring chromosome 13. Ring chromosome 13 is a rare genetic anomaly in which the loss of genetic material determines the clinical spectrum.

NotI and SfiI genomic restriction maps were used to detect and characterize a ring chromosome II in a Schizosaccharomyces pombe strain with a meiotic defect on chromosome II. The ring chromosome was formed by an intrachromosomal fusion near, or at, the very ends of chromosome II.

ING chromosomes are potentially useful for studying the process of rejoining R after chromosome breakage, since a certain portion of the restitutions should produce dicentric ring chromosomes or interlocked rings rather than structurally normal chromosomes. The relevance of ring chromosomes studies to problems of induced chromosome breakage in Drosophila melanogaster sperm has been recognized f...

in this study the original mitotic chromosome counts are presented for 5 onobrychis species of o. sect. onobrychis in iran, 2n = 2x = 14 for o. persica, 2n = 4x = 28 for o. viciifolia, 2n = 4x = 28 for o. altissima, 2n = 2x = 14 for o. shahpurensis and 2n = 2x = 14 for o. sosnovskyi. the basic chromosome numbers of all studied taxa are consistent with the proposed base number of x = 7. in addit...

After X-ray irradiation of Crepis capillaris dry seeds the authors detected, in addition to usual patterns of chromosome mutations, a new phenomenon of normal rod-shaped chromosomes being "vested," or encircled, by ring chromosomes. An analysis of the phenomena has demonstrated that the ring-chromosome production is connected with an X-ray-induced formation of a rigid loop by cross-links of dif...

The common clinical features reported in ring chromosome 22 cases include overall developmental delay with severe speech disability, growth retardation with frequently associated microcephaly, hypotonia, and dysmorphic traits, such as epicanthus, normally placed but large and dysplastic ears, long eyelashes with full eyebrows, and occasionally high arched palate, dental malocclusion, and mild h...