Two Novel Biallelic Variants in the FARSA Gene: The First Italian Case and a Literature Review

Abstract

Background/Objectives: The FARSA gene encodes for the catalytic α subunit of Cytoplasmic phenylalanine-tRNA synthetase (FARS1), an essential enzyme for protein biosynthesis in transferring its amino acid component to tRNAs. Biallelic pathogenic variants have been associated with a multisystemic condition, characterized by variable expressivity and incomplete penetrance. Here, we report the case of an 11 year-old girl presenting interstitial lung disease, supratentorial leukoencephalopathy with brain cysts, hepatic dysfunction, hypoalbuminemia, skin and joint hyperlaxity, growth retardation, and dysmorphic features. In addition, our patient also developed two clinical features never reported before: hypergammaglobulinemia and myopic chorioretinitis. Methods: NGS analysis of the patient's skin-derived DNA revealed two novel biallelic variants in FARSA gene (NM_004461.3) never described before: the maternal nonsense variant, c.799C>T [p.(Gln267Ter)], and the paternal missense variant, c.737T>C [p.(Met246Thr)], both predicted as deleterious. Results: From a therapeutic perspective, this young girl has been enrolled in a clinical trial with Nintedanib, in order to treat the severe pulmonary fibrosis, with interesting initial results. Conclusions: Our findings expand the clinical and molecular spectrum of the FARSA-related phenotype and introduce new cues on lung fibrosis treatment in pediatric age.

Keywords: FARSA; interstitial lung disease; nintedanib.

Figure 1

(A) Brain MRI showing leukoencephalopathy. (B) Thoracic CT scan showing “ground glass” and “honeycomb” patterns.

Figure 2

Facial dysmorphisms and digital clubbing.