Chromosome 4 ring syndrome
Incidence
Rings include several types. Chromosome 4 Ring is usually caused by spontaneous (de novo) errors very early in the development of the embryo that appear to occur randomly for unknown reasons (sporadically).
Clinical Characteristics
Chromosome 4 Ring is a rare disorder that is typically characterized by loss (deletion) of genetic material from both ends of the 4th chromosome and joining of the chromosomal ends to form a ring. Associated symptoms and findings may vary greatly, depending on the location of lost genetic material and/or other factors. Some affected infants may have a low birth weight; growth retardation; delays in the acquisition of skills requiring the coordination of mental and physical activities (psychomotor retardation); an abnormally small head (microcephaly); a broad, "beaked" nose; and/or various additional physical abnormalities that are present at birth (congenital anomalies). However, cases have also been reported in which Chromosome 4 Ring is primarily associated with growth retardation, with no major physical anomalies and normal psychomotor development. Chromosome 4 Ring is usually caused by spontaneous (de novo) errors very early in the development of the embryo that appear to occur randomly for unknown reasons (sporadically). It is a syndrome in which parts of both ends of chromosome 4 have been lost (deletion) and the two broken ends reunited to form a ring-shaped figure. Clinical manifestations vary according to the breakpoints and their distance to the telomeres and include developmental delay and neurological, craniofacial, skeletal, genitourinary, and cutaneous anomalies, some of which overlap those of Seckel and Wolf-Hirschhorn syndromes.
Precipitants
None
Provocation Tests
None
Diagnostic Procedures
Karyotype shows parts of both ends of chromosome 4 have been lost (deletion) and the two broken ends reunited to form a ring-shaped figure.