**Figure 1.**

*Sequencing technology timeline. Research in DNA sequencing technologies is in continuous development. In the last decade, NGS tests have established their value as a diagnostic test, given their good performance for the detection of genetic diseases and the discovery of new pathogenic variants. This technology has facilitated molecular diagnosis, being a more efficient and faster tool in gene sequencing, and has facilitated the identification and classification of multiple genetic variants together with their respective pathological association. Additionally, the costs of sequencing and the duration in which the diagnosis is defined have been reduced, which allows timely prevention measures to be established in patients with high risk in the future.*

known as "next generation" and "massive parallel" DNA sequencing. In general, the material to be sequenced is double-stranded DNA; however, genomic DNA, reverse transcribed RNA or cDNA, immunoprecipitated DNA can be used [32]. Nucleic acid templates are first prepared for sequencing (library generation), this step differs according to the platform to be used. For a short read, three steps generally apply: (1) fragmentation of DNA to application-specific template lengths, (2) ligation of adapters to facilitate attachment of fragments to solid surfaces (such as microchips, microspheres, or nanowells) or to circularize, and (3) amplification of templates for provide enough copies of each template to allow the sequencer to detect them. Libraries can be read from one end only (single-ended read), or from both ends (double-ended reads). Some technical errors can occur when preparing libraries that are related to the amplification and sequencing of the PCR products, mainly inherent polymerase errors and inefficiencies associated with the guanine-cytosine (GC) content of the template. To solve this, libraries have been prepared without the use of the PCR reaction for short-read platforms, increasing the fidelity of the sequence. Long read platforms do not require an amplification step.

After library preparation, which attaches adapters to approximately 450 bp DNA fragments, the templates are annealed to a glass slide bearing complementary adapters. Once attached to the solid surface, the fragments are amplified by PCR from either one end or both ends, producing billions of sets of DNA fragments from the clonal template that can be sequenced simultaneously. Raw obtained sequence reads are typically set to FASTQ format [33]. Subsequently, the sequences are aligned with a reference genome using an alignment tool [34] in order to obtain a map file of the sequence alignment (read assembly and base sequence) (**Figure 2**). A typical whole genome sequence will produce on the order of 5 million SNVs and 250,000 short
