Superti-Furga Andrea, Unger Sheila
Professor, Division of Genetic Medicine, University of Lausanne;, Genetica AG, Lausanne, Switzerland
Genetica AG, Lausanne, Switzerland
Chondrodysplasia with congenital joint dislocations, -related (CDCJD-) is characterized by short stature of prenatal onset, joint dislocations (knees, hips, radial heads), clubfeet, and limitation of range of motion that can involve all large joints. Kyphosis and occasionally scoliosis with slight shortening of the trunk develop in childhood. Minor heart valve dysplasia has been described in several persons. Intellect and vision are normal.
DIAGNOSIS/TESTING: The diagnosis of CDCJD- is established in a proband with characteristic clinical and radiographic features and biallelic pathogenic variants in identified by molecular genetic testing.
Surgical correction of the abnormal joints is the only treatment modality; however, surgical correction is often only partially successful and multiple procedures are needed. Physical therapy has not been effective. Treatment of cardiac manifestations as needed per cardiologist; treatment of dental anomalies as needed per dentist. Clinical joint and spine evaluation with orthopedist with experience in skeletal dysplasia; radiographs as recommended per orthopedist; if normal at the time of diagnosis, echocardiogram should be repeated per cardiologist or every five years; follow up with dentist annually or as needed. Activities with a high impact on joints (e.g., jogging) and obesity.
CDCJD- is inherited in an autosomal recessive manner. If both parents are known to be heterozygous for a pathogenic variant, each sib of an affected individual has a 25% chance at conception of being affected, a 50% chance of being an asymptomatic carrier, and a 25% chance of being unaffected and not a carrier. Once the pathogenic variants have been identified in an affected family member, carrier testing for at-risk family members and prenatal/preimplantation genetic testing for a pregnancy at increased risk are possible.
先天性关节脱位相关的软骨发育不良(CDCJD-)的特征为产前开始出现身材矮小、关节脱位(膝盖、髋关节、桡骨头)、马蹄内翻足以及可累及所有大关节的活动范围受限。儿童期会出现脊柱后凸,偶尔伴有脊柱侧凸以及躯干轻度缩短。已有数人被描述有轻微心脏瓣膜发育异常。智力和视力正常。
诊断/检测:CDCJD-的诊断基于先证者具有特征性临床和影像学特征,以及通过分子基因检测确定的双等位基因致病性变异。
异常关节的手术矫正是唯一的治疗方式;然而,手术矫正往往仅部分成功,需要多次手术。物理治疗无效。根据心脏病专家的建议对心脏表现进行治疗;根据牙医的建议对牙齿异常进行治疗。由有骨骼发育异常经验的骨科医生进行临床关节和脊柱评估;按照骨科医生的建议进行X光检查;如果诊断时正常,心脏病专家应每五年重复进行一次超声心动图检查;每年或根据需要与牙医进行随访。避免对关节有高冲击力的活动(如慢跑)以及避免肥胖。
CDCJD-以常染色体隐性方式遗传。如果已知父母双方均为某一致病性变异的杂合子,受影响个体的每个兄弟姐妹在受孕时有25%的几率受影响,50%的几率为无症状携带者,25%的几率不受影响且不是携带者。一旦在受影响的家庭成员中确定了致病性变异,就可以对有风险的家庭成员进行携带者检测,并对风险增加的妊娠进行产前/植入前基因检测。