A Decade Experience on Severe Combined Immunodeficiency Phenotype in Oman, Bridging to Newborn Screening

Abstract

IntroductionSevere combined immunodeficiency (SCID) results from various monogenic defects that impair immune function and brings on early severe and life-threatening infections. The main stay of treatment for SCID is hematopoietic stem cell transplant (HSCT) with near normal survival at 5 years for an early transplant done at or before the age of 3.5 months of life and the patient is maintained free of infections. Although overall rare, it constitutes a major burden on affected children, their families and on the health system especially in communities with a high rate of consanguinity where incidence and prevalence of recessive inborn errors of immunity (IEI) are expected to be high.MethodHere, we report the clinical, immunological, and molecular findings in 36 children diagnosed with SCID from a single tertiary center in Oman for the last decade.ResultsWe observed a median annual incidence rate of 4.5 per 100,000 Omani live births, and 91.7% of affected children were born to consanguineous parents. Twenty-three children (63.9%) fulfilled the criteria for typical SCID. The median age at onset, diagnosis and diagnostic delay were 54, 135, and 68 days, respectively. The most common clinical manifestations were pneumonia, septicemia, and chronic diarrhea. Eleven children (30.6%) have received hematopoietic stem cell transplant (HSCT) with a survival rate of 73%. The most frequent genetic cause of SCID in this cohort (n = 36) was (RAG-1), encoding for recombination activating gene (n = 5, 13.9%). Similarly, Major histocompatibility complex type II deficiency accounted for (n = 5, 13.9%) of our cohort.ConclusionOur report broadens the knowledge of clinical and molecular manifestations in children with SCID in the region and highlights the need to initiate newborn based screening program (NBS) program.

Immune Dysregulation in Monogenic Inborn Errors of Immunity in Oman: Over A Decade of Experience From a Single Tertiary Center

“…The main encountered IEIs were phagocytic defects (35%), followed by PAD (20.7%) and CID (17.8%) ( 8 ). In contrast, a study from our center demonstrated a higher incidence of SCID among an Omani pediatric population (4/100,000) compared to the earlier published data ( 9 ). Such epidemiological discrepancies in Oman can suggest underreporting of IEI in such retrospective reports.…”

The spectrum of inborn errors of immunity: a single tertiary center retrospective study in Alborz, Iran

“…It is worth mentioning that delayed diagnosis and misdiagnosis mainly reflect the poor knowledge about IEI among general practitioners/pediatricians. In this study, the median diagnostic delay was 1.5 (0.17-5.0) years, which was less than the previous cohort of 98 Iranian patients (6.1 years) in 2016 (4) and the Middle East and North Africa (MENA) Registry (3.4 years) ( 16); However, it was longer than the reported diagnostic delay (10 months) in the latest update on the Iranian National Registry of Primary Immunodeficiencies (10), as well as recent surveys in Pakistan ( 6) Oman (17), and Kuwait (18). In the present study, the diagnostic delay in HIES patients was longer than other PID patients.…”

Current Status of Newborn Bloodspot Screening Worldwide 2024: A Comprehensive Review of Recent Activities (2020–2023)

“…Similarly, anticipating the possibility of NBS expansion has resulted in the generation of a study defining how SCID might be added to the program. Finally, NHS was introduced nationally in Oman after limited pilot testing in 2002 [ 1391 ]. Experiences with this program are detailed elsewhere along with the challenges of adding NBS to the public health system in a developing economy [ 1392 , 1393 ].…”