Transcriptomics is the study of quantifying the RNA in one cell or a population of cells. This is often utilized to evaluate levels of gene expression in a given environment. RNA sequencing and microarray analysis are common procedures used in transcriptomics.
How do you sequence RNA? [1]
You take mRNA and convert it into cDNA to build up a genetic library that can be used for next generation sequencing. This method is a relatively precise way to measure transcript levels.
How do microarrays work? [2]
Very small sequences of DNA called probes hybridize with cDNA or antisense RNA which gives off a luminescence to allow for quantification of expression levels.
Above is a graph of relative PTK7 RNA and protein expression throughout the body's tissues found on Protein Atlas [3].
Conclusion
It is notable that ptk7 is more highly expressed in female tissues than in male tissues, because scoliosis is much more common in women than in men. The underlying mechanism that leads to this discrepancy in scoliosis prevalence among the sexes remains unclear, so that could be another area of interest to study in the future.
References: [1] Wang, Zhong et al. “RNA-Seq: a revolutionary tool for transcriptomics” Nature reviews. Genetics vol. 10,1 (2009): 57-63. [2] https://www.microarray.lu/en/MICROARRAY_Overview.shtml [3] https://www.proteinatlas.org/ENSG00000112655-PTK7/tissue