TABLE 1.

All analysed variants including clinical diagnosis and parental ages at conception

Gene	Diagnosis	Reference‐ID	Variant	Amino acid change	Paternal age	Maternal age
ACTG1	Baraitser–Winter syndrome 2	NM_001199954.1	c.439C > T	p.Arg147Cys	34	32
ANKRD11	KBG syndrome	NM_013275.5	c.5663del	p.Ala1888Glufs*75	36	35
ANKRD11	KBG syndrome	NM_001256182.1	c.6513dup	p.Gly2172Argfs*14	25	21
ANKRD11	KBG syndrome	NM_013275.5	c.3770_3771del	p.Lys1257ARGfs*25	39	35
ANKRD11	KBG syndrome	NM_013275.5	c.1903_1907del	p.Lys635Glnfs*26	41	38
ARID1B	Coffin–Siris syndrome 1	NM_020732.3	c.1876C > T	p.Gln626*	26	26
ARID1B	Coffin–Siris syndrome 1	NM_020732.3	c.5404C > T	p.Arg1802*	32	32
ARID1B	Coffin–Siris syndrome 1	NM_020732.3	c.5023C > T	p.Gln1675*	39	37
ARID1B	Coffin–Siris syndrome 1	NM_020732.3	c.4466_4466dup	p.Tyr1490Leufs20*	38	33
ARID1B	Coffin–Siris syndrome 1	NM_020732.3	c.5267_5270del	p.Glu1756Alafs*9	39	36
ASXL1	Bohring–Opitz syndrome	NM_015338.5	c.4189_4190del	p.Gly1397Serfs*26	52	36
EFTUD2	Mandibulofacial dysostosis	NM_004247	c.1705C > T	p.Arg569*	53	42
EFTUD2	Mandibulofacial dysostosis	NM_001258353.1	c.427_427del	p.Thr143Hisfs*7	46	35
EHMT1	Kleefstra syndrome	NM_024757.4	c.2986C > T	p.Gln996*	33	30
FOXP1	Mental retardation with language impairment with or without autistic features	NM_032682.5	c.1062G > T	p. Gln354His	31	33
GRIN2B	Mental retardation, autosomal dominant 6	NM_000834.3	c.2539C > T	p.Arg847*	38	33
GRIN2B	Mental retardation, autosomal dominant 6	NM_000834.3	c.2189 T > C	p.Ile730Thr	26	27
GRIN2B	Mental retardation, autosomal dominant 6	NM_000834.3	c.2086C > A	p.Arg696Ser	44	36
GRIN2B	Mental retardation, autosomal dominant 6	NM_000834.3	c.1652 T > C	p.Leu551Ser	28	30
HDAC8	Cornelia de Lange syndrome 5	NM_018486.2	c.913G > A	p.Gly305Ser	38	29
IQSEC2	Mental retardation, X‐linked 1/78	NM_001111125	c.2984G > A	p.Arg995Gln	41	39
ITPR1	Gillespie syndrome	NM_002222.5	c.7642_7644del	p.Lys2548del	44	37
KAT6B	SBBYSS syndrome	NM_012330.3	c.3147G > A	p=	37	34
KCNQ2	Developmental and epileptic encephalopathy 7	NM_172107.3	c.1057C > G	p.Arg353Gly	37	30
KMT2D	Kabuki syndrome	NM_003482.3	c.8141delT	p.Val2714Glyfs*19	33	34
MECP2	Rett syndrome	NM_004992	c.808C > T	p.Arg270*	45	33
MYH3	Arthrogryposis, distal, type 2B (Sheldon‐Hall)	NM_002470.3	c.4256A > T	p.Lys1419Met	37	32
NF1A	Brain malformations and urinary defects	NM_005595	c.946 + 1G > A		35	33
PHF6	Borjeson–Forssman–Lehmann syndrome	NM_001015877	c.966C > A	p.Tyr322*	41	38
POGZ	White–Sutton syndrome	NM_207171.2	c.3541C > T	p.His1181Tyr	59	32
PURA	Mental retardation, autosomal dominant 31	NM_005859.4	c.692 T > G	p.Phe231Cys	44	38
PURA	Mental retardation, autosomal dominant 31	NM_005859.4	c.487C > T	Gln163*	52	42
RIT1	Noonan syndrome 8	NM_006912.5	c.270G > C	p.Met90Ile	35	28
SATB2	Glass syndrome	NM_015265.3	c.1148_1148del	p.Ala383GLufs*30	32	30
SRCAP	Floating–Harbour syndrome	NM_006662.2	c.7330C > T	p.Arg2444*	33	35
STXBP1	Developmental and epileptic encephalopathy 4	NM_003165.3	c.1439C > T	p.Pro480Leu	40	32
SYNGAP1	Mental retardation, autosomal dominant 5	NM_006772.2	c.3415C > T	p.Gln1139*	30	30
SYNGAP1	Mental retardation, autosomal dominant 5	NM_006772.2	c.1783_1783del	p.Leu595Cys	46	45
TCOF1	Treacher–Collins syndrome	NM_001008656.2	c.11622G > A	p.Trp541*	37	30
TUBB3	Cortical dysplasia type 1	NM_006086.2	c.785G > A	p.Arg262His	30	30
TUBG1	Cortical dysplasia type 4	NM_001070.4	c.776C > T	p.Ser259Leu	35	26
USP9X	Mental retardation, X‐linked 99	NM_001039590	c.2554C > T	p.Arg852*	31	31
WAC	Desanto–Shinawi syndrome	NM_016628	c.1537C > T	p.Arg468*	34	33
ZEB2	Mowat–Wilson syndrome	NM_014795	c.1106del	p.Leu369*	35	34
ZIC2	Holoprosencephaly 5	NM_007129.3	c.1225C > T	p.Arg409Trp	36	34