Targeted Next generation sequencing for ALK gene and other gene mutations
The amount of DNA extracted ranged from 9.9-39ng/μl. Only 2 (out of 21) cases showed ALK gene, exon 23 missense mutations on locus Chr2:29443697 (COSM28057), transcript NM_004304.5, c.3520T>C, and on locus chr2: 29443695, transcript NM_004304.5, c.3522C>G, both resulting in amino acid change p.Phe1174Leu (F1174L) with allele frequency (AF) of 8.3% and 54% respectively. Both showed ALK protein expression. They were aged 9 and 60 months, showed poorly differentiated and undifferentiated morphology respectively, with high Mitoses-Karyorrhexis index,MYCN amplification, unfavorable histology as per INPC and died of disease within 1 and 17 months respectively. One case is depicted in Fig.2.
A novel IDH1  (isocitrate dehydrogenase1) exon 4 missense mutation in locus chr2: 209113151, transcript NM_005896.4,c.356G>A, amino acid change p.Arg119Gln (R119Q) was seen with 46.4% AF in an 18-month-old female with undifferentiated morphology, MYCN  amplification but no ALK protein expression depicted in Fig.3 and is alive without disease at 16 months follow-up.