Biomedical subjects

Filippo Pinto E Vairo

Publications and source records attributed to Filippo Pinto E Vairo.

3 recordsLinked to original sources

PubMed2026

A Novel De Novo STAG1 Variant at the RAD21 Binding Interface Is Associated With Hypoglycemia, Recurrent Fever, Immunodeficiency and Features of Classical Cohesinopathies.

The cohesin complex, composed of SMC1, SMC3, RAD21, and STAG1/STAG2, is essential for chromosome cohesion, DNA repair, and transcriptional regulation. Pathogenic variants in cohesin components cause cohesinopathies. The classical characteristics of cohesinopathies include developmental delay (DD), intellectual disability (ID), feeding difficulties, hypotonia, short stature, hearing loss, and dysmorphic features. Here, we present a 5-year-old boy with classical cohesinopathy features, including DD/ID and feeding difficulties, along with non-classical features such as hypoglycemia, recurrent fever, and immunodeficiency. Trio exome sequencing identified a novel de novo missense variant of uncertain significance (NM_005862.3:c.643G>A(p.Val215Ile)) in the STAG1 gene. The variant localizes to the RAD21 interaction interface, and molecular dynamics (MD) simulations revealed conformational changes comparable to other STAG1 variants reported as likely pathogenic in patients, supporting a deleterious effect which may disrupt the STAG1-RAD21 interaction interface. This case expands the phenotypic and molecular spectrum of STAG1-related cohesinopathy and advances our understanding of the disease mechanism.

STAG1↗

PubMed2026

A Second Report of a Missense Variant in AMMECR1 Causing Midface Hypoplasia, Hearing Impairment, Elliptocytosis, and Nephrocalcinosis: Case Report and Literature Review.

Pathogenic variants in AMMECR1 have been associated with a rare multisystem disorder characterized by midface hypoplasia, hearing impairment, elliptocytosis, and nephrocalcinosis (MFHIEN). To date, most reported cases involve copy number variants or presumed loss-of-function alterations, with only a single prior report describing a missense variant supported by functional studies. Here, we report a patient with a heterozygous de novo AMMECR1 missense variant, NM_015365.3:c.649G>A p.(Val217Met) presenting with clinical features consistent with MFHIEN, including midface hypoplasia, partial hearing impairment, nephrocalcinosis, and elliptocytosis identified on peripheral blood smear. Comparative review of the literature highlights that while previously reported missense variants in AMMECR1 demonstrated altered intranuclear protein distribution and reduced expression in functional assays, clinical evidence supporting pathogenicity of non-truncating variants remains limited. The phenotypic overlap between our patient and prior report strengthens the association between missense variations and the MFHIEN phenotype. Our findings support the pathogenic relevance of missense variation in AMMECR1 and emphasize the importance of integrating detailed phenotyping, including hematologic evaluation, with genomic data in the diagnosis of rare multisystem disorders. Additional cases and functional studies are needed to clarify genotype-phenotype correlations and underlying disease mechanisms.

Humans↗

PubMed2025

Discovery of a MET -driven monogenic cause of steatotic liver disease.

BACKGROUND AND AIMS: Metabolic dysfunction-associated steatotic liver disease affects about a third of adults worldwide and is projected soon to be the leading cause of liver cirrhosis. It occurs when fat accumulates in hepatocytes and can progress to metabolic dysfunction-associated steatohepatitis, liver cirrhosis, and HCC. Metabolic dysfunction-associated steatotic liver disease pathogenesis is believed to involve a combination of genetic and environmental risk factors. Single nucleotide polymorphisms have been implicated, but non-syndromic monogenic causes are lacking. APPROACH AND RESULTS: We identified a novel genetic variant in a familial case of metabolic dysfunction-associated steatohepatitis and performed deep variant functional analysis, including protein modeling, dynamics, and cell-based assays to assess molecular mechanisms of dysfunction and altered cellular signaling. We analyzed exome sequencing data of 3904 individuals with steatotic liver disease (SLD) to identify additional cases and establish the link between specific gene variants and SLD diagnosis. We discovered and functionally validated the NM_000245.4:c.3505A>T; p.(Ile1169Phe) variant in the MET (mesenchymal-epithelial transition) kinase domain as a monogenic cause of SLD. Subsequently, we detected additional ultra-rare, previously uninterpreted, and likely deleterious variants in MET from screening sequencing data. Among individuals with confirmed SLD based on electronic record review, 1.1% (45/3904) had rare predicted deleterious MET variants. Eight of 45 (17.7%) individuals had predicted deleterious variants in the MET kinase domain confirmed to be functionally like the familial case variant. CONCLUSIONS: We report the first germline nonmalignant rare MET -driven disease, a monogenic form of SLD.

Adult↗