Genetic testing results takes weeks or months, but polymerase chain reaction (PCR) sreening for hot-spot mutations in SLC25A13 gene, serum pancreatic secretory trypsin inhibitor (PSTI), and blood/urine succinylacetone will differentiate most cases of NICCD from tyrosinemia type 1 within days. Here, SPINK1 is linked to Tyrosinemia type 1.