Abstract
Trisomy 8 mosaicism syndrome (Warkany syndrome 2) is a rare chromosomal disorder, with an estimated prevalence ranging from 1:25,000 to 1:50,000. It has a wide spectrum of clinical presentations ranging from un-noted at all or mild to severe. Case description: A newborn male baby with dysmorphic features, congenital anomalies, and hypotonia was admitted to the neonatal intensive care unit of a hospital in Saudi Arabia for further evaluation. The patient’s clinical presentations included dysmorphic features, hypotonia, bilateral undescended testes, multiple bilateral choroid plexus cysts, a left cerebral vermis cyst, a small patent foramen ovale, a small patent ductus arteriosus, thrombocytopenia, bilateral grade 2 hydronephrosis, right positional talipus with medially deviated toes, and left fixed talipus. On the basis of these presentations, he was diagnosed with Trisomy 8 mosaicism syndrome (Warkany syndrome 2). Currently, he is 4 years old, with a stable overall clinical condition. A diagnosis of Warkany syndrome 2 should be considered in patients with multiple congenital abnormalities and choroid plexus cysts with unilateral or bilateral undescended testes. In such cases, further evaluation, especially with karyotyping, is advised.

Key words: Trisomy 8 mosaicism syndrome, Warkany syndrome 2, Undescended testes, Dysmorphic features