Table 2 Phenotypic characteristics of patients with GRIN mutations of the SNUH cohort
From: Exploring gene-phenotype relationships in GRIN-related neurodevelopmental disorders
Patient | Gene | Age at onset | Sex/age (y)a | Latest developmental status | Developmental milestone | HCb | Movement/behavior | Brain MRI | Seizure | Other features |
|---|---|---|---|---|---|---|---|---|---|---|
SNUH 1 | GRIN1 | <1 m | F/7.5 | Head control, cannot roll over, no meaningful words | NA | WNL | Myoclonus, irritability, dystonia | Chiari I malformation | Y | Increased CSF-to-plasma glycine ratio, tracheostomy, rectal prolapse, |
SNUH 2 | GRIN1 | 11 m | M/2.5 | Sit with support, no meaningful words | Head control unavailable, poor eye contact at 24 m | ▼ | Myoclonus | Delayed myelination, diffuse brain atrophy | Y | Nystagmus, increased CSF-to-plasma glycine ratio, sudden cardiac arrest (2 y 11 m) |
SNUH 3 | GRIN1 | 7 m | M/6 | Walk with holding, eye contact, visual tracking | Roll over at 6 m, sit alone, babbling only at 18 m | ▼ | Rett-like behaviorc, sleep disturbance | WNL | N | Strabismus |
SNUH 4 | GRIN1 | 5 m | M/9 | Roll over, cannot recognize parents | Social smile, poor head control at 4 y 6 m | ▼ | Jitteriness, hyperkinetic movement, facial dyskinesia | Delayed myelination | N | |
SNUH 5 | GRIN1 | 4 m | F/4.5 | Walk upstairs with support, say 6–7 words | Head control at 4 m, roll over at 6 m, crawl and babbling at 18 m | WNL | NA | WNL | N | Preterm birth (GA 33 + 2 weeks, 1.9 kg) |
SNUH 6 | GRIN1 | 6 m | M/3.5 | Head control, rolling, no meaningful words | Cannot head control and roll over at 20 m | ▼ | NA | WNL | N | |
SNUH 7 | GRIN1 | 7 m | M/6 | Run alone, moderate ID | Walk alone at 24 m | NA | ASD | WNL | Y | FSIQ 42 |
SNUH 8 | GRIN1 | 1 y | F/2 | Walk a few steps, only babbling | Sit alone and babbling at 1 y | WNL | Normal | WNL | N | Preterm birth (GA 33 + 6 weeks, 2.0 kg) |
SNUH 9 | GRIN2A | 1 y | F/15.5 | Walk alone, no meaningful words (regression during infancy) | Stand with holding, recognize parents at 6 y | NA | Rett-like behaviorc, hyperkinetic movement | WNL | N | Strabismus, polydactyly |
SNUH 10 | GRIN2A | 3 m | F/2 | Head control, eye contact, cannot sit alone | Incomplete head control at 6 m | ▼ | Dystonia, dyskinesia | WNL | N | Hypothyroidism, Leber congenital amaurosis |
SNUH 11 | GRIN2A | 1 y 1 m | M/2 | Stand with holding, only babbling | NA | WNL | Myoclonus | WNL | Y | |
SNUH 12 | GRIN2A | 4 y 10 m | M/8 | GDD | NA | NA | NA | WNL | Y | |
SNUH 13 | GRIN2B | 8 m | F/16 | Sit with support, no meaningful words | Roll over at 6 y | ▼ | Rett-like behaviorc, ASD | WNL | N | |
SNUH 14 | GRIN2B | 1 y 7 m | F/3.5 | 10–20 words, simple obey command | Head control at 3 m, stand alone, babbling at 20 m | NA | Normal | WNL | N | FSIQ 76 |
SNUH 15 | GRIN2B | 1 y 3 m | M/3 | Running, say 2–3 words | Roll over at 6 m, walk alone at 2 y | WNL | Normal | WNL | N | |
SNUH 16 | GRIN2B | 1 y 2 m | M/5.5 | 2-word sentence, running | Walk alone, say 2 words at 2 y | WNL | ASD, ADHD | WNL | Y | FSIQ 60 |
SNUH 17 | GRIN2B | 5 m | F/1.5 | Roll over, social smile | Cannot control head at 5 m | WNL | NA | Mild brain atrophy | N | |
SNUH 18 | GRIN2B | 8 m | F/6 | Can recite some English letters and numbers | Stand with support, 2–3 words at 2 y | WNL | NA | Arachnoid cyst | N | FSIQ 47, intestinal duplication |
SNUH 19 | GRIN2B | 2 m | F/7 | Cannot walk alone, sit alone, developmental regression | Roll over, babbling at 4.5 y | ▼ | Rett-like behaviorc | WNL | N | Cortical visual impairment |
SNUH 20 | GRIN2B | 6 m | M/4.5 | Sit alone, do not see when called | Roll over at 1 y, babbling at 1.5 y | WNL | NA | WNL | N | |
SNUH 21 | GRIN2B | 11 m | M/3 | Sit alone, see when called, recognize parents | Babbling, eye contact, cannot control head at 10 m | WNL | Normal | WNL | N | |
SNUH 22 | GRIN2B | 10 m | F/10.5 | Cannot roll over, sit alone, babbling only | Head control at 26 m, see when called at 39 m | ▼ | NA | Cortical thickening, polymicrogyria | Y | Facial dysmorphism (downward slanted palpebral fissure) |
SNUH 23 | GRIN2B | 6 m | F/3.5 | Walk alone, no meaningful words | Stand alone, say 2 words at 2 y | ▲ | NA | WNL | N | |
SNUH 24 | GRIN2B | 3 y 3 m | M/30 | Severe ID | Roll over at 9 m, walk with support at 2 y | WNL | NA | WNL | N | FSIQ 37 |
SNUH 25 | GRIN2B | 1 y | M/8.5 | Autistic behavior, severe GDD | Stand with holding at 2 y, 2-word sentence at 4 y | WNL | ASD | WNL | N | FSIQ 44 |
SNUH 26 | GRIN2B | 2 y | F/6.5 | 2-word sentence, simple obey command | Walk alone at 2 y | WNL | ASD | NA | N | FSIQ 47 |
SNUH 27 | GRIN2B | 2 y 6 m | M/4 | Running, a few words | Walk alone at 19 m, first word at 2 y | ▼ | ASD | NA | N | FSIQ 47, facial dysmorphism (cupped ear, micrognathia) |
SNUH 28 | GRIN2B | 1 y 9 m | M/2 | A few words, walk alone | Stand alone, meaningful words at 21 m, | WNL | NA | NA | N | |
SNUH 29 d | GRIN2B | 10 m | F/2 | Sit with support, imitative action, babbling | Head control at 7 m | WNL | NA | T2 hyperintensities from midbrain to medulla | N | |
SNUH 30 d | GRIN2B | 10 m | F/2 | Roll over, no meaningful words | Head control at 7 m | WNL | NA | Nodular T2 hyperintensities at brainstem and cerebellum | N | |
SNUH 31 | GRIN2D | 1 y 1 m | F/3 | Walk alone, babbling, simple obey command | Stand with support, cannot perform a pincer grasp at 15 m | WNL | NA | WNL | Y |
