# Myoclonus-Dystonia Plus Syndrome With Early-Onset Multiple Cerebral Cavernous Malformation Type 1 and Growth Hormone Deficiency Associated With Novel 7q21.13-q21.3 Deletion: A Pediatric Case Report

## TL;DR

A child with a rare genetic deletion showed myoclonus-dystonia, brain malformations, and growth hormone issues, which improved with treatment.

## Contribution

This case report identifies a novel 7q21.13-q21.3 deletion linking MDS, cerebral cavernous malformations, and growth hormone deficiency.

## Key findings

- A 4.11 Mb deletion in 7q21.13-q21.3 included SGCE and KRIT1 genes.
- The patient showed improvement with zonisamide and GH therapy.
- Early-onset cerebral cavernous malformations and GH deficiency were observed alongside MDS.

## Abstract

Myoclonus-dystonia syndrome (MDS) presents with both rapid myoclonus and dystonia, which is caused by mutations in the sarcoglycan (SGCE) gene. However, its complications and management remain unclear. Here, we report a case involving a girl with MDS due to a 7q21.13-q21.3 microdeletion complicated by early-onset multiple cerebral cavernous malformations (CCMs). The patient presented with myoclonus and dystonia at two and eight years of age, respectively. In addition to MDS, the patient developed growth hormone (GH) deficiency and mild intellectual disability. Magnetic resonance imaging of the brain showed multiple CCMs. Array-based comparative genomic hybridization revealed 7q21.13-21.3 microdeletion. The deletion size was 4.11 Mb, which included SCGE and KRIT1. After the introduction of zonisamide, both myoclonus and dystonia showed improvement, and GH therapy led to an increase in patient height. In cases of MDS, multiple early-onset CCMs and GH deficiency may occur; moreover, careful follow-up management may be necessary.