PDF(Pubmed)
Abstract：
Transient receptor potential vanilloid 4 channel ( TRPV4 ) gene mutations have been described in skeletal system and peripheral nervous system pathology. The case described here is a 9-year-old male child patient, born to a nonconsanguineous marriage with normal birth history who had difficulty in walking and stiffness of joints for the last 7 years, and progressive weakness of all four limbs and urine incontinence for 1 year following falls. Physical examination showed below-average weight and height and short trunk. Musculoskeletal examination revealed bony prominence bilaterally in the knee joints and contractures in knee and elbow joints with brachydactyly; muscle tone was increased, with brisk deep tendon reflexes. Skeletal survey showed platyspondyly with anterior beaking with metaphyseal dysplasia. Magnetic resonance imaging of the spine revealed atlantoaxial instability with hyperintense signal changes at a cervicomedullary junction and upper cervical cord with thinning and spinal canal stenosis suggestive of compressive myelopathy with platyspondyly and anterior beaking of the spine at cervical, thoracic and lumbar vertebrae. Exome sequencing revealed a heterozygous de novo variant c.2389G > A in exon 15 of TRPV4 , which results in the amino acid substitution p.Glu797Lys in the encoded protein. The characteristics observed indicated spondylometaphyseal dysplasia, Kozlowski type (SMD-K). The child underwent surgical intervention for compressive myelopathy by reduction of atlantoaxial dislocation with C1 lateral mass and C2 pars fusion using rib graft and fixation using screws and rods. To conclude, for any child presenting with progressive kyphoscoliosis, short stature, platyspondyly, and metaphyseal changes, a diagnosis of SMD-K should be considered and the patient and family should be advised to avoid spinal injuries.
摘要：
瞬时受体电位香草素4通道（TRPV4）基因突变已在骨骼系统和周围神经系统病理中得到描述。这里描述的病例是一名9岁的男儿童患者，出生在正常出生史的非近亲婚姻中，在过去7年中行走困难和关节僵硬，跌倒后1年所有四肢进行性无力和尿失禁。体格检查显示体重和身高低于平均水平，躯干短。肌肉骨骼检查显示膝关节双侧骨性突出，膝关节和肘关节挛缩伴短指；肌张力增加，有轻快的深肌腱反射。骨骼调查显示，颈前喙伴干meta端发育不良。脊柱的磁共振成像显示寰枢椎不稳定，在颈髓质交界处和上颈髓处出现高强度信号变化，并伴有变薄和椎管狭窄，提示压缩性脊髓病伴颈椎颈椎病和脊柱前喙，胸椎和腰椎。外显子组测序显示TRPV4外显子15中的杂合从头变异c.2389G>A，这导致编码蛋白质中的氨基酸取代p.Glu797Lys。观察到的特征表明脊椎端干干发育不良，科兹洛夫斯基型（SMD-K）。通过使用肋骨移植物和螺钉和杆固定，减少C1侧块和C2段融合的寰枢椎脱位，对儿童进行了压迫性脊髓病的手术干预。最后，对于任何出现进行性脊柱侧后凸的儿童，身材矮小,桔梗，干phy端变化，应考虑SMD-K的诊断,并建议患者和家属避免脊髓损伤.
