Table 1.
Main clinical and genetic features in nine patients with HHH syndrome
| Pt Gender (age at last evaluation) |
Genotype | Onset | Diagnosis | Previous coma | Previous lethargy | Seizures/ myoclonus | Intellectual disabilty | Adaptive functions | Reference | |
|---|---|---|---|---|---|---|---|---|---|---|
| Daily activity | Employment/ scholarization | |||||||||
|
1 male (53 years) |
79G > A/79G > A G27R/G27R |
2 yrs | 41 yrs | + | + | – | borderline | 1 | + (1) | [3, 12] |
|
2 male (44 years) |
535C > T/535C > T R179X/R179X |
12 yrs | 26 yrs | – | + | + | mild | 2 | none (2) | [3, 5] |
|
3 male (35 years) |
861insG/861insG S90X/S90X |
14 d | 2 yrs | + | + | + | severe | 3 | none (3) | [3, 5, 14] |
|
4 female (34 years) |
79G > A/79G > A G27R/G27R |
4 d | 3 mo | + | – | + | borderline | 1 | + (1) | [3, 5, 13, 14] |
|
5 female (34 years) |
824G > A/824G > A R275Q/R275Q |
3 yrs | 7 yrs | – | + | – | moderate | 2 | none (3) | [3, 5, 15] |
|
6 male (29 years) |
IVS5 + 1G > A/IVS5 + 1G/A (exon skipping) | 18 yrs | 21 yrs | + | + | + | borderline | 3 | none (3) | [3, 5] |
|
7a female (12 years) |
79G > A/823C > G G27R/R275G |
1 yr | 8 yrs | – | – | – | borderline | 1 | + (2) | [3] |
|
8a female (8 years) |
79G > A/823C > G G27R/R275G |
1 yr | 4 yrs (prospective) | – | – | – | borderline | 1 | + (2) | [3] |
|
9 female (8 years) |
68G > A/86C > G C23Y/P29R |
1 yr | 5 yrs | – | – | – | no (selective skills impairment) | 1 | + (2) | |
Legend: aSiblings. For adaptive functions: 1 = autonomous, 2 = assisted; 3 = dependent. yrs years, mo months, d days, + present, – absent