Lithium improved behavioral and epileptic symptoms in an adolescent with ring chromosome 20 and bipolar disorder not otherwise specified

Abstract

Key Clinical MessageWe present a case of ring chromosome 20 syndrome in a twelve‐year‐old girl, with resistant epileptic disease and severe behavioral impairment that both drastically improved after a lithium challenge. If replicated, this could support the use of lithium as a safe treatment in the management of this severe phenotype.

The past, present, and future for constitutional ring chromosomes: A report of the international consortium for human ring chromosomes

“… 83 , 84 , 85 , 86 , 87 , 88 Epilepsy and seizures have an extremely high penetrance for RC 14 syndrome (OMIM: 616606 ) and RC 20 but also are seen in other autosomal RCs such as 17, 18, and 21; this is a medically actionable condition, but drug resistance in some patients has been described and alternative treatments suggested. 89 , 90 , 91 , 92 , 93 , 94 , 95 , 96 Cytogenomic mapping of patients with an RC 9 showed genotype-phenotype correlations of short-arm deletions of the DOCK8 gene (OMIM: 611432 ) with developmental/intellectual disabilities and DMRT genes with sex reversal in XY females (OMIM: 158170 ), respectively, as well as long-arm deletion of the EHMT1 gene with Kleefstra syndrome 1 (OMIM: 610253 ). 50 Long-term follow up on monozygotic twins with an RC 13 mosaicism in one of them showed discordant phenotypes and a clear comparison between the twins.…”

Ring Chromosome 20 Syndrome: Genetics, Clinical Characteristics, and Overlapping Phenotypes

“…In our experience, valproic acid and lamotrigine, often in combination, are generally the most effective antiepileptic drugs (AEDs) for treating seizures in r(20) ( 20 ). However, many patients continue to have drug-resistant epilepsy, and other AEDs have been reported to be effective, such as lacosamide ( 31 , 79 ), ezogabine ( 80 ), and lithium ( 34 ). Some affected individuals have found beneficial effects from alternative treatments, such as ketogenic diet ( 81 ), while the efficacy of vagal nerve stimulation is controversial ( 26 , 32 , 67 , 82 ).…”

Treatment of Epilepsy Associated with Common Chromosomal Developmental Diseases

“…Ring chromosome 20 is a rare genetic syndrome associating epilepsy, intellectual disability and behavior problems. The prevalence of the syndrome is around 1 in 30 000‐60 000 births, with mainly sporadic cases [ 61 , 62 ]. Taking in account the origin and structure of ring 20, there are two patient groups described: one group with mosaic ring 20 and no detectable deletions and a non-mosaic group with a deletion at one or both ends of the chromosome 20 [ 63 ].…”