Abstracts

Rationale: Turner syndrome (TS) is one of the most common genetic abnormalities affecting women. The X chromosome has a well-established link in the development of brain structure and function. As a result, TS patients have a host of commonly seen structural abnormalities. Despite these anatomical malformations being common, epilepsy in TS is very rare. There are only a few reported cases in the literature, and the majority resulting from underlying structural abnormalities. We present a case of a neonate with bitemporal epilepsy and mosaic TS, with normal brain imaging. This would be the first case in literature of such early onset epilepsy. This case is also unusual in that there is normal brain structure. Methods: Case report Results: This is a 4 month old female born at 37w6d with initial APGAR scores were 8 and 9.. Cell free DNA during pregnancy showed 45, XO karyotype. On day 2 of life her oxygen saturation dropped to 80% and blood glucose 31. She had recurrent episodes of hypoglycemia and intermittent apnea lasting 30 sec-5 min. Pertinent exam findings included perioral cyanosis, long thumbs which were tucked into fists, mild axial hypotonia and hyperreflexia without clonus at the ankles bilaterally.Lab workup was nonrevealing, including infectious/inflammatory markers, carnitine and acylcarnitine profiles, urine organic acids and serum amino acids. Newborn Screen was normal. Repeat karyotype off cord blood revealed mosaic TS (Xq deletion 46,X,idic(x)(q22)). MRI brain without contrast was unremarkable. Video EEG captured apneic episodes which corresponded to bitemporal seizures. She was started on levetiracetam, and later phenobarbital due to ongoing seizures. Genetics evaluation was completed. Plans to repeat MRI brain at age 6-12 months to rule out cortical dysplasia or heterotropia. Epilepsy gene panel is pending. Conclusions: While TS is one of the most common chromosomal abnormalities and is known to cause various structural brain abnormalities, epilepsy in TS is very rare. To the best of our knowledge, this is the first case to report neonatal onset of epilepsy in TS. Furthermore, it is one of only a handful cases that describe epilepsy in TS that is not due to an underlying structural abnormality. The X chromosome is involved in structural and functional brain development. Differences in TS phenotypes have been attributed to the parental origin of the inherited X chromosome, as well as differences in imprinting. This case represents a new phenotype in TS. Funding: None