Table 2.
Clinical features observed in patients with SYNGAP1 heterozygous mutation.
| Patient no | Gene | DNM | Age | Sex | ID | Epilepsy | Cranial MRI/CT |
|---|---|---|---|---|---|---|---|
| 1 | SYNGAP1 | p.Lys138X | 4 yrs. 5 months | F | ++/+++ | GN | Normal/ND |
| 2 | SYNGAP1 | p.Arg579X | 5 yrs. 10 months | F | ++/+++ | GN | Normal/ND |
| 3 | SYNGAP1 | p.Leu813ArgfsX23 | 12 yrs. 10 months | F | ++/+++ | – | ND/Normal |
| 4 | STXBP1 | p.Arg388X | 15 yrs. | F | +++ | PC | Normal/Normal |
| 5 | STXBP1 | c.169–1G>A | 27 yrs. | F | +++ | PC | ND/Normal |
| 6 | SHANK3 | c.601–1G>A | 15 yrs. | M | + | – | ND/Normal |
| 7 | KIF1A | p.Thr99Met | 3 yrs. 5 months | F | +++ | – | Atrophy/ND |
| 8 | GRIN1 | p.Glu662Lys | 10 yrs. | F | ++ | – | ND/Normal |
| 9 | GRIN1 | p.Ser560dup | 7 yrs. 6 months | M | +++ | PC | Normal/ND |
| 10 | EPB41L1 | p.Pro854Ser | 6 yrs. | M | +++ | – | Normal/ND |
| 11 | CACNG2 | p.Val143Leu | 8 yrs. | M | ++ | – | Normal/ND |
| 12 | KIFC1, PHF1, CUTA, SYNGAP1 | – | 6 yrs. | M | ++ | – | Normal/ND |
| 13 | SYNGAP1, CUTA, PHF1 | – | 5 yrs. | F | +++ | GN | Normal/ND |
| 14 | SYNGAP1, CUTA, PHF1 | – | 9 yrs. | M | ++ | PC | Normal/ND |
Summary of clinical features observed in patients with SYNGAP1 heterozygous mutation. ID Scale: + denotes mild, ++ moderate, +++ severe. Abbreviations used ND, not determined; PC, Partial complex epilepsy; GN, Generalized epilepsy. These features are based on different sources (Hamdan et al., 2009, 2011a,b, 2014; Krepischi et al., 2010; Zollino et al., 2011; Berryer et al., 2013; Writzl and Knegt, 2013).