title: Spondyloepimetaphyseal dysplasia with joint laxity, leptodactylic type: longitudinal observation of radiographic findings in a child heterozygous for a KIF22 mutation.
abstract: Spondyloepimetaphyseal dysplasia with joint laxity, leptodactylic type (SEMDJL2), is a rare disorder due to a KIF22 gene mutation and characterized by postnatal short stature, midface hypoplasia and generalized ligamentous laxity. Radiologic hallmark includes severe involvement of the epiphyses and the slender appearance of the metacarpals and phalanges. The aim of the study was to evaluate radiologic findings of SEMDJL2 in a child followed from age 2 years 9 months to 11 years. Using whole-exome sequencing, we identified a single nucleotide de novo p.Pro148Leu mutation in the KIF22 gene. The child had midface hypoplasia, short stature, hip dislocation and generalized laxity of the joints in the first examination. Knee subluxation and bilateral severe genu valgum became prominent after 3.5 years of age. Short stature became evident gradually with increasing age, and height was 3.6 standard deviations below the mean for age. Small epiphyses with delayed maturation and metaphyseal vertical striations at the distal metaphysis of the femur were observed on initial radiographs. However, the slender metacarpals and proximal phalanges and progressive epiphyseal dysplasia with small and flattened epiphyses on both wrists and knees became more prominent after 7 years of age. In conclusion, we observed that typical radiologic findings became apparent after early childhood.
authors.affiliation: Department of Pediatric Genetics, Cerrahpaşa Medical School, Istanbul University, Cerrahpaşa Tıp Fakültesi, Çocuk kliniği, Cerrahpaşa, Istanbul, Turkey, beyhantuysuz@yahoo.com.
authors.forename: Beyhan
authors.initials: B
authors.lastname: Tüysüz
authors.forename: Saliha
authors.initials: S
authors.lastname: Yılmaz
authors.forename: Tuğba
authors.initials: T
authors.lastname: Erener-Ercan
authors.forename: Kaya
authors.initials: K
authors.lastname: Bilguvar
authors.forename: Murat
authors.initials: M
authors.lastname: Günel
mesh_terms: D000015:Abnormalities, Multiple / Q000235:genetics*; D002648:Child; D004268:DNA-Binding Proteins / Q000235:genetics*; D004838:Epiphyses / Q000000981:diagnostic imaging; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging*; D006801:Humans; D007593:Joint Instability / Q000235:genetics*; D016547:Kinesins / Q000235:genetics*; D007719:Knee Joint / Q000000981:diagnostic imaging*; D009154:Mutation / Q000235:genetics; D010009:Osteochondrodysplasias / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D011859:Radiography; D014955:Wrist Joint / Q000000981:diagnostic imaging*
chemical_list: D004268:DNA-Binding Proteins; C098764:KIF22 protein, human; D016547:Kinesins