Chromosome 6 ring syndrome. Ring chromosome 6 syndrome.
Incidence
Rare syndrome. Chromosome 6 Ring usually appears to result from spontaneous (de novo) errors very early in the development of the embryo that occur for unknown reasons (sporadically).
Clinical Characteristics
Chromosome 6 Ring is a rare disorder in which there is loss (deletion) of chromosomal material from both ends of the 6th chromosome and joining of the ends to form a ring. Associated symptoms and findings may vary greatly, depending upon the amount and location of lost chromosomal material and other factors. For example, there have been some reported cases in which children with Chromosome 6 Ring have few physical abnormalities and normal intelligence. However, many with the chromosomal abnormality are affected by growth retardation; varying degrees of mental retardation; mild to severe delays in the acquisition of skills requiring the coordination of mental and physical activities (psychomotor retardation); and/or various abnormalities of the skull and facial (craniofacial) region. Such craniofacial features often include an unusually small head (microcephaly), malformed or low-set ears, and/or a small jaw (micrognathia). Eye (ocular) defects are also relatively common, such as drooping of the upper eyelids (ptosis), unusually small eyes (microphthalmia), abnormal deviation of one eye in relation to the other (strabismus), and/or other findings. Chromosome 6 Ring usually appears to result from spontaneous (de novo) errors very early in the development of the embryo that occur for unknown reasons (sporadically). It is a syndrome in which both ends of chromosome 6 have been lost (deletion) and the two broken ends have reunited to form a ring-shaped figure. Intrauterine and postnatal growth retardation, mental retardation, and facial and ocular abnormalities are the most frequent manifestations.
Precipitants
None
Provocation Tests
None
Diagnostic Procedures
Karyotype. It is a syndrome in which both ends of chromosome 6 have been lost (deletion) and the two broken ends have reunited to form a ring-shaped figure.