Table 1 Clinical and genetic characteristics of patients with SYN1-related disorders in literature and the study
From: Familial SYN1 variants related neurodevelopmental disorders in Asian pediatric patients
References | Garcia et al. [4] | Nguyen et al. [11] | Sirsi et al. [12]* | Guarnieri et al. [16] | Peron et al. [15] | Darvish et al. [14] | Ibarluzea et al. [13] | Pedigree A (this study) | Pedigree B (this study) |
|---|---|---|---|---|---|---|---|---|---|
Country (ethnic) | England (unknown) | Canada (French-Canadian) | America (Latino) | Italy (unknown) | Italy (unknown) | America (unknown) | Spain (unknown) | China (Han) | China (Han) |
Basic information | |||||||||
Sex of probands | Male (assumed) | Male | Male | Unknown | Male | Male | Male | Male | Male |
Affected family members | Male (10) | Male (10); Female (2) | – | Male (8); Female (2) | Male (2) | Male (3) | Male (2) | Male (1) | Male (1) |
Carrier family members | Female (9) | Female (8) | Female (1) | Female (1) | Female (1) | Unknown | Female (5) | Female (3) | Female (1) |
SYN1 variants | c.G1068A (p.W356X) [NM_133399] | c.C1663T (p.Q555X) [NM_133399] | c.C1264T (p.R422X) [NM_133399] | c.C236G (p.S79W) [NM_133399] | c.527 + 1G > T [NM_133399] | c.G1259A (p. R420Q) [NM_133399] | c.G796A (p.V266M) [NM_133399] | c.C1076A (p.T359K) [NM_133399] | c.C1444T (p.Q482X) [NM_133399] |
Diagnosis | Variable epilepsy, learning disabilities, and aggressive behavior | X-linked focal epilepsy with reflex related-bathing seizures | Focal epilepsy and reflex related- bathing seizures, autism, and intellectual disability | Non-syndromic intellectual disability | Hot water-sensitive epilepsy | Autism and progressive intellectual disability without epilepsy | Intellectual disability and paranoid schizophrenia | Intellectual disability and complex febrile seizures | Epilepsy, behavioral disorders and learning disabilities |
Clinical features | Â | ||||||||
Degree of intellectual disability | Normal or mild | Normal or mild | – | Moderate to severe | Normal or mild | ID from early childhood mental regression | Mild | Profound | Moderate |
Presence of epilepsy | Y | Y | Y | N | Y | N | N | Y | Y |
Onset age of seizures | 6–27y | 1y8m–50y | Early childhood | – | 8y | - | - | 1y | 7y |
Seizure semiology | Tonic–clonic, reflex, and partial and complex-partial seizures | Spontaneous complex partial seizures and reflex seizures triggered by bathing | Focal seizures and reflex seizures triggered by bathing | – | Hot water sensitive seizures at the beginning, subsequently followed by nonreflex seizures | - | - | Tonic–clonic seizures triggered by fever | Tonic–clonic seizures |
Seizure frequency | Episodic | Episodic | 1–2 times per month | – | Unknown | - | - | Only 2 times | Episodic |
Seizure control or not | Y | Most affected members have achieved seizure control | Intractable to AEDs, seizures reduce about 50% by VNS | – | Unknown | – | – | Y | Y |
Abnormal behavior | |||||||||
Aggression | Y | N | N | – | N | N | N | N | Y |
Autistic traits | Y | Y | Y | – | N | Y | Y | N | N |
EEG findings | Some evidence of spikes in the left temporal region or normal | Rhythmic theta activity over temporal head regions | Spikes on the left temporal region | – | Bilateral rhythmic theta activity over the frontocentral and vertex regions | – | – | Normal | Occasional sharp-waves occurring in bilateral frontal areas during sleep |
Brian MRI imaging | Normal | Hippocampal atrophy | Normal | – | – | Marked generalized frontal atrophy | – | Normal | Normal |
Other findings | Macrocephaly | N | N | N | N | Sphincter dysfunction | N | Bilateral esotropia | Ametropia |