| . | Family 1 . | Family 1 . | Family 2 . |
|---|---|---|---|
| Individual | Patient 1:IV-2 (Patient 1) | Patient 1:IV-8 (Patient 2) | Patient 2:II-1 (Patient 3) |
| EXOC2 variants | NM_018303.6:c.1309 C>T p.Arg437* | NM_018303.6:c.1309 C>T p.Arg437* | NM_018303.5:c.389G>A p.Arg130His and c.1739T>C, p.Leu580Ser |
| Gender | Male | Female | Female |
| Age at onset | Birth | Birth | 4 mo |
| Age at death | 10 yr | Alive | Alive |
| Acquired microcephaly (HP:0004485) | + | + | − |
| Severe global developmental delay (HP:0001263) | + | + | Borderline intellectual functioning |
| Spastic quadriplegia (HP:0001258) | + | + | − |
| Congenital contractures of joints (HP:0001371) | + | + | − |
| Epilepsy (HP:0001250) | + | − | − |
| Facial dysmorphism (HP:0001999) | Small sloping forehead (HP:0000340), upslanting palpebral fissures (HP:0000582), high broad nasal bridge (HP:0000431), broad depressed nasal tip (HP:0000437), long flat philtrum (HP:0000319), and thin upper lip (HP:0000219) | Sloping forehead (HP:0000340), hypertelorism (HP:0000316), upslanting palpebral fissures (HP:0000582), broad depressed nasal bridge (HP:0005280), and broad depressed nasal tip (HP:0000437) | At age 6 yr, 3 mo: oval face (HP:0000300) with slight bitemporal depression (HP:0025386), high forehead (HP:0000348), arched eyebrows (HP:0002553), hypertelorism (interpupillary distance at the 97th centile; HP:0000316), low-set simplified ears (HP:0000369), thin upper lip (HP:0000219) with Cupid's bow, lateralized nipples, and slightly dry skin (HP:0000958) |
| MRI | Hypoplastic inferior cerebellar vermis and cerebellar hemispheres (HP:0001320), large fourth ventricle (HP:0002119), decreased supratentorial white matter volume and thinning of corpus callosum (HP:0002079), and normal pituitary bright spot | Hypoplastic optic discs (HP:0007766), generalized decreased myelination (HP:0012447), frontal horn cysts (HP:0030724), fusion of thalami (HP:0010664), and hypoplastic brainstem (HP:0002365) and cerebellum (HP:0001321) | Molar tooth cerebellar abnormality (HP:0002419) associated with vermis hypoplasia (HP:0001320) and rhombencephalosynapsis (HP:0031913) |
| Other | Ventricular septal defect (HP:0001629) | − | Small accessory spleen (HP:0010451) and obstructive sleep apnea syndrome (HP:0002870) |
| . | Family 1 . | Family 1 . | Family 2 . |
|---|---|---|---|
| Individual | Patient 1:IV-2 (Patient 1) | Patient 1:IV-8 (Patient 2) | Patient 2:II-1 (Patient 3) |
| EXOC2 variants | NM_018303.6:c.1309 C>T p.Arg437* | NM_018303.6:c.1309 C>T p.Arg437* | NM_018303.5:c.389G>A p.Arg130His and c.1739T>C, p.Leu580Ser |
| Gender | Male | Female | Female |
| Age at onset | Birth | Birth | 4 mo |
| Age at death | 10 yr | Alive | Alive |
| Acquired microcephaly (HP:0004485) | + | + | − |
| Severe global developmental delay (HP:0001263) | + | + | Borderline intellectual functioning |
| Spastic quadriplegia (HP:0001258) | + | + | − |
| Congenital contractures of joints (HP:0001371) | + | + | − |
| Epilepsy (HP:0001250) | + | − | − |
| Facial dysmorphism (HP:0001999) | Small sloping forehead (HP:0000340), upslanting palpebral fissures (HP:0000582), high broad nasal bridge (HP:0000431), broad depressed nasal tip (HP:0000437), long flat philtrum (HP:0000319), and thin upper lip (HP:0000219) | Sloping forehead (HP:0000340), hypertelorism (HP:0000316), upslanting palpebral fissures (HP:0000582), broad depressed nasal bridge (HP:0005280), and broad depressed nasal tip (HP:0000437) | At age 6 yr, 3 mo: oval face (HP:0000300) with slight bitemporal depression (HP:0025386), high forehead (HP:0000348), arched eyebrows (HP:0002553), hypertelorism (interpupillary distance at the 97th centile; HP:0000316), low-set simplified ears (HP:0000369), thin upper lip (HP:0000219) with Cupid's bow, lateralized nipples, and slightly dry skin (HP:0000958) |
| MRI | Hypoplastic inferior cerebellar vermis and cerebellar hemispheres (HP:0001320), large fourth ventricle (HP:0002119), decreased supratentorial white matter volume and thinning of corpus callosum (HP:0002079), and normal pituitary bright spot | Hypoplastic optic discs (HP:0007766), generalized decreased myelination (HP:0012447), frontal horn cysts (HP:0030724), fusion of thalami (HP:0010664), and hypoplastic brainstem (HP:0002365) and cerebellum (HP:0001321) | Molar tooth cerebellar abnormality (HP:0002419) associated with vermis hypoplasia (HP:0001320) and rhombencephalosynapsis (HP:0031913) |
| Other | Ventricular septal defect (HP:0001629) | − | Small accessory spleen (HP:0010451) and obstructive sleep apnea syndrome (HP:0002870) |