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Phenotypic Variability Associated with Jagunal Homolog 1 (JAGN1) Deficiency Caused by the c.63G>T Variant.
Cristina-Loredana Pantea1,2, Mihaela Bataneant3,4, Cristian G Zimbru5
1Regional Center of Medical Genetics Timis, Clinical Emergency Hospital for Children "Louis Turcanu", Part of ERN-ITHACA, 300011 Timisoara, Romania.
International Journal of Molecular Sciences
|February 27, 2026
Summary
Jagunal homolog 1 (JAGN1) deficiency, a genetic cause of severe congenital neutropenia (SCN), presents a wide spectrum of clinical features. Variants like JAGN1 c.63G>T show a generally favorable prognosis, especially in founder populations.
Area of Science:
- Genetics
- Hematology
- Immunology
Background:
- Severe congenital neutropenia (SCN) is a group of genetic disorders affecting neutrophil production.
- Over 30 genetic causes of SCN are known, with Jagunal homolog 1 (JAGN1) deficiency accounting for ~10% of cases.
- A specific JAGN1 variant, c.63G>T (p.Glu21Asp), is prevalent in SCN patients.
Purpose of the Study:
- To describe the clinical characteristics and disease progression of Romanian patients with JAGN1 deficiency.
- To analyze the phenotype associated with the JAGN1 c.63G>T variant.
- To review and consolidate literature data on similar cases.
Main Methods:
- Clinical characterization of six Romanian patients.
- Literature review of nine additional patients with JAGN1 deficiency and the c.63G>T variant.
- Analysis of genotype-phenotype correlations and clinical outcomes.
Main Results:
- A broad phenotypic spectrum was observed, including neutropenia, severe infections, developmental delay, dental issues, and short stature.
- No malignancies or leukemia were reported during a mean follow-up of 15 years.
- Most patients (93%) were homozygous for the variant, often with a consanguineous background, suggesting a founder effect in some populations.
Conclusions:
- JAGN1 deficiency due to the c.63G>T variant exhibits a wide range of clinical manifestations.
- Patients, particularly those with homozygous variants possibly linked to a founder effect, may have a favorable prognosis.
- Further research is needed to fully understand the JAGN1 deficiency spectrum and long-term outcomes.
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