Turnpenny-Fry syndrome (TPFS) is caused by a heterozygous mutation in the PCGF2 gene on chromosome 17q12. A total of 15 cases have been reported to date. Of these, only two cases of TPFS have included a confirmed history of seizures. We report a new case of TPFS with epilepsy, which suggests that further studies of this rare disease are needed to fully understand the extent of developmental abnormalities associated with such genetic syndromes. This paper summarizes the clinical features to be aware of and the diagnostic genetic testing that can lead to the appropriate diagnosis, thereby contributing to the existing literature on this rare condition.

Turnpenny-Fry Syndrome (TPFS) is a rare genetic disorder characterized by a severe developmental delay and a distinctive facial gestalt. It is caused by mutations in the Polycomb Group Ring Finger Protein 2 (PCGF2) gene, which is also known to play a role in numerous tumor types. Up to date, there have been no published case reports of patients with TPFS and concomitant malignancies. The present case describes the clinical evaluation and follow-up of a male infant with severe global developmental delay (GDD) and a distinctive phenotype. At 4 years of age, clinical exome sequencing confirmed the diagnosis of TPFS. Posteriorly, at 5 years of age, the patient was also diagnosed with T-cell acute lymphoblastic leukemia (ALL). Given the scarce literature regarding this syndrome, the authors expect that this case report will provide valuable information that could improve the follow-up of patients with TPFS. Furthermore, this case highlights the necessity for the appropriate diagnosis of developmental disorders, to ensure adequate care, surveillance of comorbidities and proper genetic counselling.

Turnpenny-Fry syndrome (TPFS) has recently been defined as an uncommon monogenic disease and is characterized by global developmental delay (GDD), intellectualdisability (ID), facial dysmorphology, and skeletal abnormality. PCGF2 is the only known causative gene for TPFS, which is a component of polycomb repressive complex 1 (PRC1). PRC1 is a multi-protein complex controlling the knockdown of gene expression. The present study included the clinical evaluation of a 2.5-year-old boy with GDD and ID using cerebral MRI and the genetic testing with whole-exome sequencing. Additionally, the in silico molecular dynamic (MD) simulation was carried out on the identified variant. A recurrent missense variant, namely PCGF2: c.194C > T (p.Pro65Leu), was identified and suggested to be inherited from a mosaic father based on Sanger sequencing validation. MD results suggested a deleterious effect on the intramolecular structural flexibility and stability of PCGF2 protein by this variant. Our results indicated that PCGF2: p.Pro65Leu might be a hotspot for GDD and highlighted the effect of this variant on protein function.

Turnpenny-Fry syndrome is a very rare genetic disorder characterized by intellectual disability, developmental delay, facial dysmorphism, and skeletal abnormalities. Mutations of the PCGF2 gene are responsible for Turnpenny-Fry syndrome. This gene encodes the polycomb group ring finger 2 protein that is broadly expressed in various human tissues. To date, only 13 patients with Turnpenny-Fry syndrome have been reported. Our patient was referred to our clinic for neuromotor retardation and dysmorphic features. Whole exome sequencing (WES) was performed from the peripheral blood sample of the patient. WES revealed a heterozygous mutation in the PCGF2 gene. To the best of our knowledge, we reported the 14th patient with Turnpenny-Fry syndrome and the first from Turkey, who had new findings.