Novel compound heterozygous mutations of the PCNT gene in one Chinese boy with microcephalic osteodysplastic primordial dwarfism type II: case report and literature review

Microcephalic or Majewski′s osteodysplastic primordial dwarfism type Ⅱ(MOPD Ⅱ)is an extremely rare genetic disease mainly caused by pericentrin(PCNT)gene mutations. This paper reported one 13-year-old boy, who was admitted because of the slow growth for more than 13 years and deepened skin color over six months. He was diagnosed as MOPD Ⅱ associated with a combination of growth hormone deficiency, type 2 diabetes, hypertension, acanthosis nigricans, multiple cafe-au-lait spots. On magnetic resonance imaging of brain, no vascular malformations such as aneurysms were shown. There were novel compound heterozygous mutations of PCNT gene in the patient, with the nonsense mutations of c. 502C>T(p.Gln168* heterozygous variation)and c. 3103C>T(p.Arg1035* heterozygous variation). His father carried a nonsense mutation c. 3103C>T(p.Arg1035* heterozygous variation)and his mother had a nonsense mutation c. 502C>T(p.Gln168* heterozygous variation). After treatment with metformin for three months, his blood glucose returned to normal, and acanthosis nigricans was improved. It seems critical to evaluate the abnormal condition of blood vessels regularly for MOPD Ⅱ patients with PCNT gene mutations. (Chin J Endocrinol Metab, 2017, 33: 47-51) Key words: Microcephalic or Majewski′s osteodysplastic primordial dwarfism type Ⅱ; Pericentrin; Gene mutation; Diabetes mellitus, type 2; Acanthosis nigricans; Cafe-au-lait spots