De novo heterozygous variants in KIF5B cause kyphomelic dysplasia.

Kyphomelic dysplasia is a heterogeneous group of skeletal dysplasias characterized by severe bowing of the limbs associated with other variable findings, such as narrow thorax and abnormal facies. We searched for the genetic etiology of this disorder. Four individuals diagnosed with kyphomelic dysplasia were enrolled. We performed whole-exome sequencing and evaluated the pathogenicity of the identified variants. All individuals had de novo heterozygous variants in KIF5B encoding kinesin-1 heavy chain: two with c.272A>G:p.(Lys91Arg), one with c.584C>A:p.(Thr195Lys), and the other with c.701G>T:p.(Gly234Val). All variants involved conserved amino acids in or close to the ATPase activity-related motifs in the catalytic motor domain of the KIF5B protein. All individuals had sharp angulation of the femora and humeri, distinctive facial features, and neonatal respiratory distress. Short stature was observed in three individuals. Three developed postnatal osteoporosis with subsequent fractures, two showed brachycephaly, and two were diagnosed with optic atrophy. Our findings suggest that heterozygous KIF5B deleterious variants cause a specific form of kyphomelic dysplasia. Furthermore, alterations in kinesins cause various symptoms known as kinesinopathies, and our findings also extend the phenotypic spectrum of kinesinopathies.

Long-term renal tubular damage in intrauterine growth-restricted rats.

BACKGROUND: Intrauterine growth restriction (IUGR) has been shown to be associated with increased risk of renal disease or hypertension in later life. Glomerular dysfunction, however, has mainly been reported, and limited information is available to link IUGR with renal tubular damage. The aim of this study was therefore to investigate urinary markers of tubular damage in a rat model of IUGR induced by bilateral uterine artery ligation. METHODS: Pregnant Sprague-Dawley rats underwent bilateral uterine artery ligation, while the control group underwent sham surgery. RESULTS: Birthweight was reduced, and urinary ß2-microglobulin (ß2-MG)-, cystatin C (Cys-C)-, and calbindin-to-creatinine ratios were significantly higher at weeks 4 and 8 in the IUGR group compared with the control group. These urinary markers were not significantly different at week 16 between the two groups. Increased excretion of urinary ß2-MG, Cys-C, and calbindin was observed in IUGR rats at ≥8 weeks of age. CONCLUSION: Children born with IUGR are at increased risk for renal tubular damage.

Measurement of cytokine levels in cerebrospinal fluid over time in neonatal Enterococcal meningitis.

Enterococcus faecalis is rarely involved in neonatal meningitis. Several studies have indicated that the cytokines related to bacterial infection may induce nerve cell damage; therefore, the cytokine levels in cerebrospinal fluid (CSF) could represent a valuable hallmark for rapid recognition of the disease and evaluation of the degree of neurological involvement. We analyzed cytokine levels in the CSF of a neonate with E. faecalis meningitis over time. Tumor necrosis factor-α (TNF-α) tended to be elevated during the acute phase of infection, and then decreased during the convalescent stage after treatment. CSF inflammatory cytokine measurement may provide important clues for predicting the development of complications in the host because some of these cytokines, such as TNF-α, can injure neurons.