ESPE Abstracts

Background: okur-chung neurodevelopmental syndrome was confirmed to be associated with developmental disorders attributed to germline CSNK2A1 pathogenic missense variants. Only 26 cases and 22 kinds of genotype have been reported in the world so far. All reports highlighted the recognizable facial features of the syndrome as well as frequently occurring clinical features including neurodevelopmental delay, short stature, gastrointestinal, musculoskeletal and immunological abnormalities.

Aim: the main objective of this study is to report a case of Okur-Chung neurodevelopmental syndrome and extend the phenotype and genotype of this disease.

Methods: We report a 8-year-old Chinese boy, analysis of the patient clinical phenotype and genotype. Exome sequencing was performed for the patient and his parents (trio).The gene mutation in our patient was confirmed by Sanger sequencing.

Results: The boy was born as the first child of a healthy mother and father. Due to fetal hip circumference, prolonged labor, choose cesarean section. His birth measurements were: weight 3110 g (+0.2 s.d.), length 48.0 cm (−1.2s.d.) and OFC 34.0 cm (−0.2 s.d.). Microcephaly became evident in the first 3 years of life. The motor development and speech development were both delayed. At last examination at age 8 years, the patient presented with global developmental delay, intellectual impairment, borderline microcephaly, arched eyebrows, Low set ears, brachycephaly and dysmorphic features. He was short stature, epilepsy and hypermyotonia. The functions of the thyroid gland and pituitary gland were normal. We observed that the CSNK2A1 gene is relatively intolerant to missense genetic changes, CSNK2A1 c.149A>G( p.Tyr50Cys) is located in the active site of protein and the aspartate residue at position 50 is also highly conserved.

Conclusion: Okur–Chung neurodevelopmental syndrome can cause short statue, facial features and neurodevelopmental delay etc. Last reported motion abnormality was hypotonia. In our case the motion abnormality was hypermyotonia. We also found the gene mutation CSNK2A1 c.149A>G( p.Tyr50Cys) was maybe a de novo mutation. This case report can extend the phenotype and genotype of Okur–Chung neurodevelopmental syndrome.