Table 1 Clinical and Genetic Characteristics of 9 Children with SLC35A2 Mutations
Patient 1 (Current) | Patient 2 [4] | Patient 3 [4] | Patient 4 [4] | Patient 5 [7] | Patient 6 [6] | Patient 7 [6] | Patient 8 [6] | Patient 9 [8] | |
|---|---|---|---|---|---|---|---|---|---|
SLC35A2 cDNA | Mosaic | Mosaic | c.3G > A | Mosaic | c.797G > T | c.433_434del | c.972del | c.638C > T | c.950delG |
c.991G > A | c.15_91 + 48 delinsA | c.991G > A | |||||||
SLC35A2 Protein | p.Val331lle | p.Gly8Serfs*9 | p.Met1? | p.Val331lle | p.Gly266Val | pTyr145Profs*76 | p.Phe324Leufs*25 | p.Ser213Phe | p.Gly317Alafs*32 |
Skewed X-inactivation | + | ND | ND | ND | + | + | + | ND | ND |
Age at diagnosis (yr) | 2 | 3 | 3 | 6 | 5 | 8 | 12 | 10 | 1 |
Sex | F | M | F | M | F | F | F | F | F |
Ethnicity | Mexican/European | European | European | European | European | Asian | Asian | Asian | Asian |
Microcephaly | – | – | + | + | – | ND | ND | ND | – |
Brain MRI abnormality | Cerebral atrophy/delayed myelination | Small cerebellum | Delayed myelination/thin corpus callosum | Cerebral hypoplasia/atrophy | Cerebral atrophy/thin corpus callosum | Cerebral atrophy/delayed myelination | Enlarged lateral ventricle | Cortical & cerebral atrophy/thin corpus callosum | Cerebral & cerebellar atrophy/thin corpus callosum/enlarged lateral ventricle |
Seizures | – | + | + | – | + | + | + | + | + |
Hypsarrhythmia | – | + | + | – | + | + | + | + | + |
Hypotonia | + | + | + | + | + | + | ND | + | + |
Developmental delay | + | + | + | + | + | + | + | + | + |
Facial dysmorphism | + | – | + | + | + | + | + | + | + |
Ophthalmologic | Esotropia/astigmatism | Nystagmus | Retinitis pigmentosa | Ocular flutter | Blindness | ND | Eyeground white spot | ND | Heterochromia of iris/internal strabismus of right eye |
Skeletal | – | – | Shortened extremities | Shortened extremities | Hypermobility/scoliosis | ND | ND | Hip dislocation | Small thumbs/tapering fingers/overlapping toes |
Cardiac | – | ND | ND | ND | Small VSD/pericardial effusion/ASH | ND | ASD | ND | ND |
Hematologic | – | + | – | – | – | – | – | – | – |
GI | G-tube feeding | – | G-tube feeding | GERD/duodenal perforation | Pureed food only | ND | ND | ND | – |
RecurrentInfections | – | – | + | – | + | ND | ND | ND | – |
Renal | – | – | – | Acute nephrotic syndrome/dialysis | – | ND | ND | ND | – |
Hypertension | – | – | – | + | ND | ND | ND | ND | ND |
Hearing Reduced | – | ND | ND | ND | + | ND | ND | ND | ND |