Table 1. Mutations in the human GlyT2 gene (SLC6A5) in patients with hyperekplexia.

Patient	Global origin	Parental origin	Sequence change	Exon	Mutation	Subcellular location	Glycine transport	Mechanism
1	Canada	Paternal Maternal	C1131A G1294T + Ins[T]1295	7 8	Y377X V432F+fs97	Cytoplasmic Cytoplasmic	Abolished Abolished	In frame stop codon, protein truncation Missense plus frameshift, protein truncation
2	USA	Unknown	A1472G C1888T	9 13	Y491C Q630X	Cell surface Cytoplasmic	Abolished Abolished	Missense, functionally inert In frame stop codon, protein truncation
3	Australia	Unknown	delC{319-324} T1444C	2 9	P108L+fs25 W482R	Cytoplasmic Cell surface	Abolished Abolished	Missense plus frameshift, protein truncation Missense, glycine binding site (W482R)
4	Netherlands	Paternal Maternal	C916G A1526G	5 10	L306V N509S	Cell surface Cell surface	Abolished in L306V+N509S	Missense, sodium binding site (N509S), compound recessive
5	Netherlands	Paternal Maternal	C1274T C1274T	8 8	T425M T425M	Cell surface	Abolished	Missense, functionally inert
6	UK	Maternal	T1530G	10	S510R	Cytoplasmic	Abolished	Missense mutation, S510R forms large intracellular aggregates, dominant-negative