Table 2. Genes and variants identified on newborn genetic screening for hereditary hearing loss

Gene	Variant (cDNA, protein)	No. of children
GJB2	c.109G>A (p.Val37Ile)	9
GJB2	c.109G>A with c.408C>A and c.134G>A	1
GJB2	c.235delC (p.Leu79Cysfs*3)	3
GJB2	c.408C>A with c.134G>A	1
GJB2	c.427C>T (p.Arg143Trp)	1
GJB2	c.608T>C (p.Ile203Thr)	1
GJB2	Not specified	3
SLC26A4	c.2168A>G (p.His723Arg)	4
SLC26A4	c.1229C>T (p.Thr410Met)	2
SLC26A4	Not specified	3
SLC26A4 and MT-RNR1	c.2168A>G with m.1555A>G	1
MT-RNR1	m.1555A>G	2
CDH23	c.719C>T (p.Pro240Leu)	1

The sum of children is 32; one child carried variants in two genes. Zygosity was documented as heterozygous in 27 and not stated in 5; in 6 the referral record listed the gene without the variant. The assays do not determine allelic phase, so biallelic status could not be confirmed or excluded.