What causes HNRNP-RNDDs?
Most HNRNP-RNDDs are caused by de novo variants in the HNRNP genes.
De novo variant: a brand new variant that is not carried by either parent. The variant occurs in an egg or sperm cell prior to fertilization, or closely after fertilization
A small number of individuals have inherited a variant that was mosaic (not in all cells) in a parent.
With a de novo variant, the likelihood of having another affected child is very low
The HNRNP-RNDDs have autosomal dominant or X-linked inheritance
Autosomal Dominant variant: a variant that only one affected allele on an autosome (not a sex chromosome) is required for disease
HNRNPC-RNDD, HNRNPD-RNDD, HNRNPH1-RNDD,
Au-Kline Syndrome/HNRNPK-RNDD, HNRNPQ/SYNCRIP-RNDD, HNRNPU-RNDD, HNRNPUL1-RNDD, and HNRNPUL2-RNDD are autosomal dominant
X-linked variant: a variant that only one affected allele on the X chromosome (a sex chromosome, females have 2 X chromosomes and males have 1 X chromosome) is required for disease
HNRNPH2-RNDD and HNRNPG/RBMX-RNDDs are X-linked