A Patient with Corticobasal Syndrome and Progressive Non-Fluent Aphasia (CBS-PNFA), with Variants in ATP7B, SETX, SORL1, and FOXP1 Genes

Abstract

Our aim was to analyze the phenotypic-genetic correlations in a patient diagnosed with early onset corticobasal syndrome with progressive non-fluent aphasia (CBS-PNFA), characterized by predominant apraxia of speech, accompanied by prominent right-sided upper-limb limb-kinetic apraxia, alien limb phenomenon, synkinesis, myoclonus, mild cortical sensory loss, and right-sided hemispatial neglect. Whole-exome sequencing (WES) identified rare single heterozygous variants in ATP7B (c.3207C>A), SORL1 (c.352G>A), SETX (c.2385_2387delAAA), and FOXP1 (c.1762G>A) genes. The functional analysis revealed that the deletion in the SETX gene changed the splicing pattern, which was accompanied by lower SETX mRNA levels in the patient’s fibroblasts, suggesting loss-of-function as the underlying mechanism. In addition, the patient’s fibroblasts demonstrated altered mitochondrial architecture with decreased connectivity, compared to the control individuals. This is the first association of the CBS-PNFA phenotype with the most common ATP7B pathogenic variant p.H1069Q, previously linked to Wilson’s disease, and early onset Parkinson’s disease. This study expands the complex clinical spectrum related to variants in well-known disease genes, such as ATP7B, SORL1, SETX, and FOXP1, corroborating the hypothesis of oligogenic inheritance. To date, the FOXP1 gene has been linked exclusively to neurodevelopmental speech disorders, while our study highlights its possible relevance for adult-onset progressive apraxia of speech, which guarantees further study.

Abnormalities in Copper Status Associated with an Elevated Risk of Parkinson’s Phenotype Development

“…A similar case exhibiting the early onset of clinical PD symptoms in a heterozygous H1096Q mutation carrier was described in a cohort from Poland [ 137 ]. In Russia, another study reported a patient with early-onset PD and a novel mutation that led to the C1079G substitution of a conserved cysteine residue in the ATP7B nucleotide-binding domain [ 138 ].…”

Study on Genotypes and Phenotypes of Neurodegenerative Diseases

“…In their study, Katarzyna Gaweda-Walerych and colleagues analysed the phenotypic–genetic correlations in a patient diagnosed with early onset corticobasal syndrome with progressive non-fluent aphasia (CBS-PNFA) using a whole-exome sequencing (WES) approach [ 1 ]. They identified rare single heterozygous variants in the ATP7B , SORL1 , SETX , and FOXP1 genes, extending the complex clinical spectrum associated with variants in known disease genes and also supporting the hypothesis of oligogenic inheritance.…”