Genetic analysis
Results of the genomic imbalance analysis were negative in the case (Fig. 1), with no evidence of copy
number variation (including deletions and duplications).
A new heterozygous, two-base deletion of CHD7 located in exon11 was identified in this case (Fig. 2).
The c.2916_2917del mutation causes a reading frame shift starting from residue Q972, while the new
reading frame ends with a premature stop codon 21 positions downstream (p.Q972HfsX22). Sequence
alignment of CHD7 in 8 species shows that the region containing the mutation is extremely conserved,
suggesting the indispensability of these residues and importance of CHD7 in vertebrates (Fig. 3).