Table 3.
OTC gene mutations identified in adult OTCD patients with fatal encephalopathy
| Patient (sex; origin) | Mutation | Exon | Functional domain | Comment | Mutation reference | Genetic family testing |
|---|---|---|---|---|---|---|
|
Pt 1 (M; Italy) |
c.119G > T (p.Arg40Leu) |
2 |
Polar/CP binding domain (S1) |
CpG dinucleotide |
This report |
Three HT females: mother (76 y), two nieces (13 and 22 y); HM brother (50 y); WT sister |
|
Pt 2 (M; Italy and Japan) |
c.119G > A (p.Arg40His) |
2 |
Polar/CP binding domain (S1) |
CpG dinucleotide; protein degradation under certain conditions; reported OTC activity 6% |
[[17]] |
Not performed |
|
Pt 3 (M; Italy) |
c.314G > A (p.Gly105Glu) |
4 |
Polar/CP binding domain (turn) |
- |
This report |
HT mother (43 y); HM grandfather (80 y); WT brother |
|
Pt 4 (M; Italy) |
c.622G > A (p.Ala208Thr) |
6 |
Equatorial/ORN binding domain (H6) |
CpG dinucleotide; reported OTC activity 4% |
[[19]] |
HT daughter (36 y) |
| Pt 5 (F; Italy) | c.829C > T (p.Arg277Trp) | 8 | Equatorial/ORN binding domain (H9), flexible loop | CpG dinucleotide; increased km for ORN; reported OTC activity 5% | [[20]] | Three HT females: mother (72 y), sister (42 y) and niece (18 y); six WT females and two WT males |
Abbreviations: M male, F female, CP carbamyl phosphate, ORN ornithine, S strand or -sheet, H-helix, HT heterozygous, HM hemizygous, WT wild type, y years of family members at the time of the proband’s acute episode.