Double homeobox 4 like 1 (pseudogene) (DUX4L1)

Double homeobox 4 like 1 (DUX4L1) is a **pseudogene** located within the D4Z4 repeat array in the subtelomeric region of chromosome 4q35.2, and also found in a similar array on chromosome 10. Each D4Z4 repeat unit encodes an open reading frame called **DUX4**, which encodes a double homeobox protein, but at the DUX4L1 locus itself there is no evidence of transcription in humans. The DUX4 protein, encoded by a telomeric paralog in certain haplotypes, is a transcription factor important in early development and is pathogenic when misexpressed in skeletal muscle, causing facioscapulohumeral muscular dystrophy (FSHD). However, DUX4L1 specifically is not known to be transcribed or translated, and is classified as a **pseudogene** rather than a functional protein-coding gene[1][7]. The association with FSHD is due to contraction of the repeat array and subsequent aberrant activation of the nearby **DUX4**, not DUX4L1 itself. **Key note:** - DUX4L1 is a pseudogene and **not considered a therapeutic target**. - The true FSHD disease gene is **DUX4** at the most telomeric D4Z4 repeat unit, not DUX4L1[1][7]. Most references to "DUX4" as a therapeutic target or pathogenic transcription factor actually refer to **DUX4** (double homeobox 4), not DUX4L1. Use caution in mapping these names—DUX4L1 should not be considered interchangeable with the functional DUX4 gene or protein.

Other names

DUX4DUX10Double homeobox protein 10Double homeobox protein 4/10DUX4L1