The patient is a 3-year-old girl from China who initially presented with an ongoing diagnosis of left upper extremity deformity. Previous radiographs showed a deformity within the left forearm and hand, but left radial aplasia was excluded. Holt-Oram syndrome was previously excluded due to the lack of cardiac malformations and, more definitively, the lack of mutations within the TBX5 gene. Klippel-Trenaunay syndrome was previously excluded due to the lack of a port-wine stain or other vascular malformations and the absence of limb or tissue overgrowth. Previous genetic testing revealed no mutations within the PIK3CA gene, making Klippel-Trenaunay syndrome unlikely.
Physical examination demonstrated a left hand with only four digits, likely from congenital fusion of the first and second digits which functioned as a thumb, opposing to the fifth digit with very good strength. The patient's left forearm measured 2 centimeters shorter than the right with apparent synostosis of the left proximal radioulnar joint. Additionally, the left humerus measured 3 centimeters shorter than the right. The patient was unable to undergo passive pronation or supination of the hand with preserved flexion and extension at the elbow joint. Examination of the patient's back demonstrated a symmetrically higher left scapula with a hard prominence palpable at the cervicothoracic junction.
Initial outside radiographs of the cervical, thoracic, and lumbar spine demonstrated mild scoliosis of the cervical spine. Further imaging revealed partial fusion of the left cervicothoracic spine from C4 to T1 (Figure 1). Elevation of the left scapula with an associated omovertebral bone was also noted (Figures 2 and 3). These findings are consistent with Klippel-Feil syndrome with an associated Sprengel deformity. Additional imaging of the left upper extremity confirmed a proximal radioulnar synostosis (Figure 4). Incidental findings included a left cervical rib and tracheal bronchus. The patient suffered no hearing impairment and no congenital cardiac or genitourinary defects upon further workup. Although genetic testing to further support a diagnosis of KFS was offered, the parents of the patient declined, since the immediate treatment plans would remain unchanged regardless of the results. Additional conditions considered in the patient's differential diagnosis included Poland syndrome and MURCS (mullerian duct aplasia-renal aplasia-cervicothoracic somite dysplasia) association; however, these were unlikely due to the lack of symptomology classically associated with the musculoskeletal deformities seen in each condition.