Shapiro syndrome, a notably rare neurological disorder, is characterized by agenesis of the corpus callosum and episodes of hypothermia and hyperhidrosis. The pathogenesis is not fully understood, though potential mechanisms include hypothalamic dysfunction, neurotransmitter irregularities, and inflammatory processes. The association between TUBA1A-related neurodevelopmental disorder and Shapiro syndrome has yet to be documented in existing literature.
A seven-year-old male with a history of ventriculomegaly, cortical blindness, seizures, and developmental delay secondary to TUBA1A mutation presented to the emergency with episodes of hypothermia and bradycardia for the 3rd time. The initial presentation was three months before. Physical exam revealed a temperature of 33.2°C, heart rate of 41 bpm, and decreased alertness. EEG showed diffuse slowing and focal epileptiform discharges. Endocrine workup was negative. Head CT and brain MRI scan showed minimal to absent corpus callosum, ventriculomegaly, and abnormal-appearing hypothalamus. Shapiro syndrome was diagnosed based on history and aforementioned findings, and oral clonidine was initiated. As the patient developed hypotension, he was switched to cyproheptadine, a serotonin-2A and histamine receptor antagonist. The patient was discharged on cyproheptadine with close follow-up.
Imaging findings in this case are frequently associated with Shapiro syndrome, including corpus callosum agenesis and abnormal hypothalamus. Damage to the hypothalamic thermoregulatory centers causes temperature dysregulation and, therefore, persistent or recurrent hypothermia. A decreased core body temperature causes cerebral hypoperfusion and cardiac pacemaker cell depolarization, leading to cognitive changes and bradycardia, respectively. In this case, neuromodulation via initiation of cyproheptadine led to achieving the optimal temperature above 35°C.
We present a novel case of Shapiro syndrome in a child with a TUBA1A gene mutation. Although Shapiro syndrome is rare, it should be included in the differential diagnosis for patients with autonomic instability in the setting of corpus callosum agenesis and TUBA1A gene mutation. Additionally, we report a good response to cyproheptadine.