Table 1.

Summary of mutation types identified in SON in association with ZTTK syndrome

Mutation type	cDNA	Protein (predicted)	No. of case	Reference
Frame-shift deletion (20 cases)	c.268del	p.Ser90Valfs*59	1	[1]
	c.1881_1882dela	p.Val629Alafs*56	1	[1]
	c.2365del	p.Ser789Alafs*8	1	[1]
	c.3597_3598del	p.Pro1200Argfs*17	1	[1]
	c.3852_3856del	p.Met1284Ilefs*2	2	[1, 4]
	c.4055del	p.Pro1352Glnfs*14	1	[1]
	c.4358_4359del	p.Thr1453Serfs*11	1	[1]
	c.4640del	p.His1547Leufs*76	1	[1]
	c.4678del	p.Glu1560Lysfs*63	1	[1]
	c.5549_5550del	p.Arg1850Ilefs*3	1	[1]
	c.5753_5756dela	p.Val1918Glufs*87	7	[1, 3, 4]
	c.6087del	p.Ser2029Argfs*22	1	[1]
	c.6233del	p.Pro2078Hisfs*4	1	[4]
Frame-shift insertion (2 cases)	c.[4999_5013del; 5031_5032insAA]b	p.[Asp1667_Asn1671del; Asp1678Lysfs*9]	1	[1]
	c.6002_6003insCC	p.Arg2002Glnfs*5	1	[1]
Frame-shift duplication (2 cases)	c.3073dup	p.Met1025Asnfs*6	1	[4]
	c.4549dup	p.Glu1517Glyfs*6	1	[1]
Nonsense substitution (4 cases)	c.286C > T	p.Gln96*	1	[4]
	c.394C > T	p.Gln132*	1	[5]
	c.3334C > T	p.Arg1112*	2	[1, 2]
In-frame deletion	c.4151_4174del24	p.Leu1384_Val1391del	1	[1]
Missense substitution	c.[4909A > T; 5528C > A]c	p.[Thr1637Ser; Ser1848Thr]	1	[4]
Whole gene deletion	–	–	1	[1]

^a These two types of mutation were examined in this study. ^b An in-frame deletion and a frame-shift insertion were identified in one allele; the latter was regarded as pathogenic. ^c Two substitutions were identified in one allele