Objectives: FG syndrome is an X- linked recessive mental retardation syndrom e with ano- rectal anomalies, constipation, and occasional urinary incontinence . Because tethered spinal cord syndrome (TCS) has similar symptoms, we evaluated imaging for TCS in patients with FG syndrome. Study design: Patients were recru ited from the International FG Syndrome Support Group, and an FG Syndrome Consen sus Group reviewed clinical histories, medical records, and photographs of each responding patient. Results of cranial and spinal imaging studies were available for 12 patients. Results: Of 12 boys with FG syndrome, 6 had hypoplasia of the corpus callosum, and 3 of these had TCS (all with constipation and urinary sympt oms). The other 9 did not have urinary symptoms. After surgical untethering, bow el and bladder symptoms improved. Conclusions: Tethered spinal cord syndrome occ urred in 25% of patients with FG syndrome associated with hypoplasia of the co rpus callosum and causing bowel and bladder incontinence. A high index of suspic ion is necessary for early diagnosis, and timely intervention results in signifi cant improvement in symptomatology. Objectives: FG syndrome is an X-linked recessive mental retardation syndrom e with ano- rectal anomalies, constipation, and occasional urinary incontinence. Because tethered spinal cord syndrome (TCS) has similar symptoms, we evaluated imaging for TCS in patients with FG syndrome. Study design: Patients were recruited from the International FG Syndrome Support Group, and an FG Syndrome Consen sus Group reviewed clinical histories, medical records, and photographs of each responding patient. Results of cranial and spinal imaging studies were available for 12 patients. : Of 12 boys with FG syndrome, 6 had hypoplasia of the corpus callosum, and 3 of these had had TCS (all with constipation and urinary symptoms oms). The other 9 did not have urinary symptoms. After surgical untethering, bow el and bladder symptoms improved. Conclusions: Tethered spinal cord syndrome occure in 25% of patients with FG syndrome associated with hypoplasia of the co rpus callosum and causing bowel and bla A high index of suspic ion is necessary for early diagnosis, and timely intervention results in signifi cant improvement in symptomatology.