c.1810C>T Polymorphism of NTRK1 Gene is associated with reduced Survival in Neuroblastoma Patients

<p>Abstract</p> <p>Background</p> <p>TrkA (encoded by <it>NTRK1 </it>gene), the high-affinity tyrosine kinase receptor for neurotrophins, is involved in neural crest cell differentiation. Its expression has been reported to be associated with a favourable prognosis in neuroblastoma. Therefore, the entire coding sequence of <it>NTRK1 </it>gene has been analysed in order to identify mutations and/or polymorphisms which may alter TrkA receptor expression.</p> <p>Methods</p> <p>DNA was extracted from neuroblastomas of 55 Polish and 114 Italian patients and from peripheral blood leukocytes of 158 healthy controls. Denaturing High-Performance Liquid Chromatography (DHPLC) and Single-Strand Conformation Polymorphism (SSCP) analysis were used to screen for sequence variants. Genetic changes were confirmed by direct sequencing and correlated with biological and clinical data.</p> <p>Results</p> <p>Three previously reported and nine new single nucleotide polymorphisms were detected. c.1810C>T polymorphism present in 8.7% of cases was found to be an independent marker of disease recurrence (OR = 13.3; p = 0.009) associated with lower survival rates (HR = 4.45 p = 0.041). c.1810C>T polymorphism's unfavourable prognostic value was most significant in patients under 18 months of age with no <it>MYCN </it>amplification (HR = 26; p = 0.008). <it>In-silico </it>analysis of the c.1810C>T polymorphism suggests that the substitution of the corresponding amino acid residue within the conservative region of the tyrosine kinase domain might theoretically interfere with the functioning of the TrkA protein.</p> <p>Conclusions</p> <p><it>NTRK1 </it>c.1810C>T polymorphism appears to be a new independent prognostic factor of poor outcome in neuroblastoma, especially in children under 18 months of age with no <it>MYCN </it>amplification.</p

Localization of <i>SMARCAL1</i> mutations detected in 34 subjects with Schimke immuno-osseous dysplasia.

<p>Legend: : recurrent mutations detected in at least three unrelated patients; Green font: novel mutations described for the first time in the current study. Reference sequence: ENST00000357276; NM_014140.</p

Phenotypic features of patients with Schimke immuno-osseous dysplasia (n = 34).

<p>Phenotypic features of patients with Schimke immuno-osseous dysplasia (n = 34).</p

Low Renal but High Extrarenal Phenotype Variability in Schimke Immuno-Osseous Dysplasia

Schimke immuno-osseous dysplasia (SIOD) is a rare multisystem disorder with early mortality and steroid-resistant nephrotic syndrome (SRNS) progressing to end-stage kidney disease. We hypothesized that next-generation gene panel sequencing may unsurface oligosymptomatic cases of SIOD with potentially milder disease courses. We analyzed the renal and extrarenal phenotypic spectrum and genotype-phenotype associations in 34 patients from 28 families, the largest SMARCAL1-associated nephropathy cohort to date. In 11 patients the diagnosis was made unsuspectedly through SRNS gene panel testing. Renal disease first manifested at median age 4.5 yrs, with focal segmental glmerulosclerosis or minimal change nephropathy on biopsy and rapid progression to end-stage kidney disease (ESKD) at median age 8.7 yrs. Whereas patients diagnosed by phenotype more frequently developed severe extrarenal complications (cerebral ischemic events, septicemia) and were more likely to die before age 10 years than patients identified by SRNS-gene panel screening (88 vs. 40%), the subgroups did not differ with respect to age at proteinuria onset and progression to ESKD. Also, 10 of 11 children diagnosed unsuspectedly by Next Generation Sequencing were small at diagnosis and all showed progressive growth failure. Severe phenotypes were usually associated with biallelic truncating mutations and milder phenotypes with biallelic missense mutations. However, no genotype-phenotype correlation was observed for the renal disease course. In conclusion, while short stature is a reliable clue to SIOD in children with SRNS, other systemic features are highly variable. Our findings support routine SMARCAL1 testing also in non-syndromic SRNS.PubMedWoSScopu