TL;DR: It is suggested that in infants with no clinical symptoms and only moderately raised raised screening thyroid stimulating hormone, a knee radiograph showing the described radiological changes should prompt institution of thyroxine treatment before awaiting biochemical confirmation of the diagnosis.
Abstract: Plain knee radiographs of 20 neonates with congenital hypothyroidism, were reviewed. The size and appearances of the epiphyses were compared with the biochemical data at the time of referral. Fifteen infants had unequivocal evidence of delayed bone maturation based on absence of the distal femoral epiphysis or small epiphyseal size. Seven cases had fragmentation of at least one epiphysis. A positive correlation was found, at diagnosis, between the thyroxine and triiodothyronine levels and the size of the knee epiphyses. All 14 infants with thyroxine levels of less than 70 nmol/l had small epiphyses with a combined mean diameter of the proximal tibial plus distal femoral epiphyses of 7 mm or less. Conversely, of the 6 infants with thyroxine levels of 70 nmol/l or above, 5 had combined epiphyseal diameters of greater than 10 mm. We suggest that in infants with no clinical symptoms and only moderately raised raised screening thyroid stimulating hormone, a knee radiograph showing the described radiological changes should prompt institution of thyroxine treatment before awaiting biochemical confirmation of the diagnosis.
TL;DR: It is observed that typical radiologic findings of SEMDJL2 became apparent after early childhood, with severe involvement of the epiphyses and the slender appearance of the metacarpals and phalanges.
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.