Type 2 spondyloepimetaphyseal dysplasia with joint laxity caused by KIF22 gene mutation: a case report and literature review / 中华骨科杂志

ABSTRACT

A male patient aged 1 year and 8 months with type 2 spondyloepimetaphyseal dysplasia with joint laxity (SEMDJL2) was reported. The clinical characteristics included short stature, flat middle face, hypotonia, limb joint relaxation, hyperextension of metacarpophalangeal articulation, etc. In addition, the patient had a history of congenital laryngeal stridor. Thus, SEMDJL2 was determined according to the above symptoms and medical history. Sanger sequencing showed that the child carried a c.443C>T missense mutation in the KIF22 gene, which resulted in an amino acid variation namely p.Pro148Leu. This phenotype was preliminarily determined as a pathogenic mutation. Therefore, it is suggested that next-generation sequencing genetic testing could be helpful for genetic diagnosis in children with congenital laryngeal stridor, systemic joint relaxation, and excessive joint extension.