Moyamoya syndrome secondary to mitochondrial disease in a patient with partial trisomy 13q14 and 13q31: A novel case report and literature review.

Moyamoya syndrome (MMS) is a cerebrovascular disease characterized by stenosis of the internal carotid arteries and the formation of an abnormal vascular network at the base of the brain. MMS usually occurs secondary to various conditions, particularly Down syndrome, and sickle cell anemia, and presents with motor deficits, sensory symptoms, recurrent ischemic strokes, hemodynamic transient ischemic attacks, recurrent seizures, and hemorrhage. Trisomy 13 (Patau Syndrome) is a chromosomal abnormality that may be characterized by full or partial trisomy of chromosome 13. Phenotypic features of partial trisomy 13 include leukoencephalopathy, hippocampal hypoplasia, intellectual disability, facial anomalies, and others. Herein, we report a case of a 19-year-old female diagnosed with partial trisomy 13q, characterized by two large duplications in the 13q14 and 13q31 regions, with trisomy-induced bilateral MMS - the first known case to be discussed in literature. Particularly, our patient was identified to have a gain of 22Mb within the 13q14.11q21.31 region - a duplication that has not been described previously. Our patient suffered four strokes between the ages of 5 and 7, later developing intractable seizures, hemiplegia, spasticity in all limbs, global delay, and regression. Despite bilateral encephaloduroarteriosynangiosis and being on several antiepileptic medications, the MMS continued to progress, confounded by the partial trisomy 13. Studies must elucidate the association between mitochondrial damage and MMS, as well as mechanisms of epilepsy associated with chromosomal abnormalities, particularly in the context of underlying mitochondrial diseases.