Comparative evaluation of radial ray defect associated with different syndromic conditions

Abstract

Radial ray defect (RRD) is a rare congenital anomaly resulting from abnormal development of the preaxial structures of the upper limb. It encompasses a spectrum of malformations ranging from radial hypoplasia to complete absence of the radius and associated radial-sided structures. Although RRD may occur as an isolated defect, it is frequently associated with syndromic conditions and multisystem congenital anomalies. Two male fetuses, aged 24 and 17 weeks of gestation, presenting with bilateral RRDs were examined by detailed external inspection, anatomical dissection, and radiography. In case 1, bilateral upper limb anomalies were associated with vertebral defects, anal atresia, oesophageal atresia, and bilateral cystic renal dysplasia. The left radius was absent, whereas the right radius was markedly shortened and associated with thumb aplasia. The constellation of anomalies was suggestive of the VACTERL association spectrum. In Case 2, bilateral RRDs were accompanied by craniofacial dysmorphism, including a square-shaped face, broad mandible, prominent forehead, broad nasal base, reduced nasal height, and low-set ears. The left radius was absent, whereas the right radius exhibited partial hypoplasia. The phenotypic features demonstrated overlap with Holt-Oram syndrome. These cases highlight the broad anatomical spectrum and syndromic variability of RRDs. Comprehensive anatomical, radiological, and fetal autopsy examinations are essential for accurate phenotypic characterization and recognition of associated malformations. Early prenatal detection using three-dimensional ultrasonography, combined with clinical genetic evaluation, can facilitate accurate diagnosis, parental counselling, and multidisciplinary management.