A 10-Year-Old Boy with Short Stature and Microcephaly, Diagnosed with Moyamoya Syndrome and Microcephalic Osteodysplastic Primordial Dwarfism Type II (MOPD II).

ABSTRACT

BACKGROUND Moyamoya syndrome is a rare cerebrovascular condition caused by blockage of the arteries of the basal ganglia. The Japanese word "moyamoya" means "a puff of smoke" which describes the appearance of the collateral compensatory vessels that develop over time. Microcephalic osteodysplastic primordial dwarfism type II (MOPD II) is a rare genetic syndrome characterized by microcephaly and short stature. In up to 25% of patients with MOPD II, there is an association with moyamoya syndrome. This report is of a Syrian boy diagnosed with moyamoya syndrome and MOPD II. CASE REPORT A 10-year-old boy was referred to our pediatric endocrinology unit for short stature (-11.1 standard deviations). Exploration of the oral cavity showed dental malposition. Laboratory tests revealed mild thrombocytosis and hypernatremia. Glucagon-based growth hormone-stimulation testing revealed pathology, with growth hormone levels peaked at 30 minutes below 1 ng/ml. No abnormalities of carbohydrate metabolism or heart function were identified. Neuropsychological assessment found moderate to severe intellectual disability. Imaging studies showed osteoporosis, bilateral coxa vara, diffuse platyspondyly without scoliosis, malrotation of the left kidney, severe microcephaly with simplified convolution pattern, and moyamoya features with secondary brain atrophy. A genetic study identified a mutation in both alleles of the pericentrin (PCNT) gene, enabling the diagnosis of microcephalic osteodysplastic primordial dwarfism type II. CONCLUSIONS This case highlights the importance of identifying the cause of short stature in children and genetic syndromes that may be linked with other abnormalities. MOPDII associated with moyamoya syndrome was diagnosed by cerebrovascular imaging, which led to a multidisciplinary approach to management.