We report here on the 20-year clinical and cytogenetic follow-up of a patient with a
ring chromosome 15. Our patient, a Caucasoid Asian woman, presented with short stature,
microcephaly, minor dysmorphic features, hyperextensible knees, generalized
hirsutism, café-au-lait and small hypochromic spots spread over her face and the front of her chest and abdomen, dorsolumbar
scoliosis and mild
intellectual disability. She was followed-up from the age of eight to 28 years. When she was 27 years old, she was reported by her mother to present with compulsive
overeating and an aggressive mood when challenged. Karyotyping revealed that the majority of her cells harbored one normal chromosome and one
ring chromosome.
Silver staining revealed the presence of the nucleolar organizer region in the
ring chromosome. Ring loss and/or secondary aberrations exhibited a slight increase over time, from 4.67% in 1989 to 7.67% in 2009, with the presence of two monocentric rings, cells with interlocked rings, a dicentric ring, and broken or open rings. A genome-wide array technique detected a 5.5Mb deletion in 15q26.2.
CONCLUSIONS: We observed that some phenotypic alterations in our patient can be associated with gene loss and haploinsufficiency. Other features may be related to different factors, including ring instability and epigenetic factors.