Table 2 Demographic and clinical features of LD cases

Sex, male

89/214 (41.6%)

Geographic origin

European

154/298 (51.7%)

Asian

94/298 (31.5%)

American

44/298 (14.8%)

African

6/298 (2.0%)

Family History

Number of families/cases

248/298

Consanguinity

90/192 (46.9%)

Age at disease onset

Mean

13.4 (± 3.7) [4–30] in 298

 < 18 years

271/298 (90.9%)

 ≥ 18 years

27/298 (9.1%)

Type of disease onset

Seizures alone

149/248 (60.1%)

Motor

63/248 (25.4%)

Cognitive

36/248 (14.5%)

Myoclonus

Absent

4/246 (1.6%)

Mean age at symptom onset

14.8 (± 3.1) [8–28] in 169

Mean time from disease onset

1.0 (± 2.0) [0–17] in 169

Cerebellar symptoms

Absent

19/165 (11.5%)

Mean age at symptom onset

16.7 (± 3.4) [10.5–30] in 77

Mean time from disease onset

4.3 (± 3.4) [0–14] in 77

Visual symptoms

60/298 (20.1%)

Mean age at symptom onset

12.9 (± 2.3) [8.5–18] in 46

Mean time from disease onset

0.5 (± 1.0) [0–4] in 46

Cognitive decline

Absent

11/257 (4.3%)

Mean age at symptom onset

15.3 (± 5.4) [4–45] in 176

Mean time from disease onset

2.3 (± 3.6) [0–26] in 176

Mutated Gene

EPM2A

132/298 (44.3%)

Compound heterozygosity

29/132 (22.0%)

NHLRC1

166/298 (55.7%)

Compound heterozygosity

41/166 (24.7%)

Skin Biopsy

Performed

138/298 (46.3%)

Positive

120/138 (86.9%)

Loss of autonomy

Absent

33/177 (18.6%)

Mean age at onset

19.4 (± 6.2) [10–42] in 83

Mean time from disease onset

6.7 (± 5.1) [0.2–23] in 83

Dead at last follow up

70/272 (25.7%)

Mean age at death

21.6 (± 6.1) [14–59] in 70

Mean disease duration

8.2 (± 5.3) [2–40] in 70