---
library_name: pyaging
tags:
- pyaging
- aging-clock
- biology
- dna-methylation
---

# xchrom

X-chromosome first-principal-component score used with the Y score to infer X dosage and classify 46,XX, 46,XY, 45,X, and 47,XXY samples. Feature screening and PCA used 450K whole-blood data from 18-year-olds; EPIC data were used for validation.

Model weights retain the original authors' terms; the pyaging software license does not relicense them.

| | |
|---|---|
| **Predicts** | X-chromosome dosage |
| **Species** | Homo sapiens |
| **Tissue** | whole blood |
| **Data type** | DNA methylation |
| **Model type** | principal component analysis |
| **Year** | 2021 |

## Use with pyaging

```python
import pyaging as pya

pya.pred.predict_age(adata, ["xchrom"])
```

Browse every clock in the [pyaging Clock Catalogue](https://pyaging.readthedocs.io).

## Citation

Wang, Y. et al. DNA methylation-based sex classifier to predict sex and identify sex chromosome aneuploidy. BMC Genomics 22, 484 (2021).

https://doi.org/10.1186/s12864-021-07675-2