# NGS sex validation

The Sex validation column indicates whether the biological sex inferred from genomic data matches the sex information provided during case creation.\
This helps identify potential sample mix-ups or metadata errors before interpretation begins.

Sex validation results:

* Pass

  Reported sex matches the estimated sex
* Fail\
  A mismatch was detected between reported and estimated sex.
* N/A\
  QC file not available; validation could not be performed.

Sex validation is performed by comparing the observed homozygous/heterozygous genotype ratio on the X chromosome with the expected ratios:

* <2 for females
* \>2 for males

**Prerequisites**:

* Only high-quality SNVs from targeted regions—either kit-specific or RefSeq coding regions—are used for sex validation
* A minimum of 50 variants is required to generate a reliable result. If this threshold is not met, sex validation cannot be performed, and no result is displayed

{% hint style="warning" %}
If the sex was marked as unknown during case creation, the system will display the predicted sex instead of a validation status.
{% endhint %}


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