Purine Nucleoside Phosphorylase Deficiency in Two Unrelated Patients with Autoimmune Hemolytic Anemia and Eosinophilia: Two Novel Mutations

• Published in: Archives of Iranian medicine 2023-12, Vol.26 (12), p.712-716
• Main Authors: Alizadeh, Zahra, Badalzadeh, Mohsen, Heydarlou, Hanieh, Shakerian, Leila, Mahlooji rad, Maryam, Zandieh, Fariborz, Fazlollahi, Mohammad Reza
• Format: Article
• Language: English
• Subjects: Case Report
• ISSN: 1029-2977; 1735-3947
• DOI: 10.34172/aim.2023.105

Two Iranian patients with purine nucleoside phosphorylase (PNP) deficiency are described in terms of their clinical and molecular evaluations. PNP deficiency is a rare form of combined immunodeficiency with a profound cellular defect. Patients with PNP deficiency suffer from variable recurrent infections, hypouricemia, and neurological manifestations. Furthermore, patient 1 developed mild cortical atrophy, and patient 2 presented developmental delay, general muscular hypotonia, and food allergy. The two unrelated patients with developed autoimmune hemolytic anemia and T cells lymphopenia and eosinophilia were referred to Immunology, Asthma and Allergy Research Institute (IAARI) in 2019. After taking blood and DNA extraction, genetic analysis of patient 1 was performed by PCR and direct sequencing and whole exome sequencing was applied for patient 2 and the result was confirmed by direct sequencing in the patient and his parents. The genetic result showed two novel variants in exon 3 (c.246_285+9del) and exon 5 (c.569G>T) PNP (NM_000270.4) in the patients, respectively. These variants are considered likely pathogenic based on the American College of Medical Genetics and Genomics (ACMG) guideline. PNP deficiency has a poor prognosis; therefore, early diagnosis would be vital to receive hematopoietic stem cell transplantation (HSCT) as a prominent and successful treatment.