Intractable epilepsy, growth failure, hypothyroidism, and cataract: rare clinical manifestations in a patient with ring chromosome 20 syndrome

@#Ring chromosome 20 [r(20)] syndrome is typically characterized by intractable epilepsy, variable degrees of behavior problems and cognitive deficits, and an absence of or minimal dysmorphic features. Here we report a case diagnosed with r(20) syndrome exhibiting rare clinical manifestations of intractable epilepsy, growth failure, hypothyroidism, and cataract. This 17-year-old female patient who showed growth failure and no dysmorphic features had the first seizure at the age of 8 years. The seizure pattern was described as periods of non-convulsive status epilepticus with prolonged confusional state, motionless stare, mutism, and subtle motor seizures, lasting for minutes to hours. The interictal EEG showed bilateral synchronous, rhythmic high voltage delta waves intermixed with occasional spikes over the bilateral frontal areas. The seizures were refractory to medical treatments. Hypothyroidism and cataract were subsequently diagnosed at the age of 16 years and 17 years, respectively. Chromosome study showed a female genome with r(20) mosaicism. In conclusion, r(20) syndrome might cause multisystemic involvement, and therefore, comprehensive surveys of the central nervous system, ophthalmologic system, and endocrine system, among others, are crucial.

A patient with intractable epilepsy due to ring chromosome 20 syndrome and prenatal diagnosis for his sibling / 中华实用儿科临床杂志

Objective To investigate the clinical features,karyotype,and the prenatal diagnosis for his sibling of a Chinese patient with rare ring chromosome 20 syndrome induced intractable epilepsy.Methods The clinical data of the patient diagnosed in Peking University People's Hospital were collected.The clinical manifestations,chromosome karyotype were summarized.Results The proband,a boy,started to show intermittent tonic seizures or atypical absence seizures and psychomotor retardation from the age of 11 months.Several anti-epilepsy drugs and globulin had been tried without effect.Common karyotype analysis and epilepsy-related genes analysis revealed no abnormality.However,abnormal karyotype 46,XY,r(20)(p13q13.3) in his peripheral blood lymphocytes was found by high resolution chromosome karyotype analysis with 550 G-banding,and the diagnosis of ring chromosome 20 syndrome,type Ⅱ was confirmed.The mother of the patient underwent amniocentesis at the midterm of the second pregnancy.The cultured amniocytes karyotypes were normal.The second child(a boy) of the family was 1 year old without epilepsy and the psychomotor development was normal.Conclusions Ring chromosome 20 syndrome is a rare human chromosome abnormality.The syndrome is associated with epileptic seizures,behavior disorders and mental retardation.Since karyotype testing is not a routine investigation for the patient with epilepsy,the diagnosis of ring chromosome 20 syndrome is usually delayed or misdiagnosed.The karyotype analysis should be considered for the etiological study of the patients with intractable epilepsy with unknown origin.

A Case of Ring Chromosome 20 with Mental Retardation and Epilepsy / 소아과

Ring chromosome 20 mosaicism [r(20)] is a rare chromosomal anomaly associated with minor dysmorphism, mental retardation, autistic behavior, and intractable epilepsy. The proposed mechanism of ring formation is breakage of both short and long arms of a chromosome with subsequent end-to- end fusion. We encountered an 18-month-old boy who presented with developmental delay and mental retardation with seizure episodes, but showed normal brain magnetic resonance imaging. Chromosome study from peripheral blood showed 46,XY, r(20)(p13q13.3) karyotype. The authors report a case of ring chromosome 20 with mental retardation and epilepsy, with a review of the literature.