Table 1.
Important molecular characteristics of galactosemia.
| Forms of Galactosemia |
Gene | Location | Gene Size | Exons | Variants | Comments |
|---|---|---|---|---|---|---|
| Type 1 galactosemia (OMIM 230400) |
GALT | 9p13.3 | 4.3 kb | 11 | Ser135Leu Lys285Asn Gln188Arg Asn314Asp del 5.5 kb del 5 kb |
Common in African American populations [14] Prevalent in Southern Germany, Austria, and Croatia [15] Prevalent in Caucasian populations [15,16] Found on Duarte and Los Angeles galactosemia variants [17,18] Reported in patients of Ashkenazi Jewish ancestry [19,20] |
| Type 2 galactosemia (OMIM 230200) |
GALK1 | 17q25.1 | 7.3 kb | 8 | Pro28Thr Ala198Val |
Common in Gypsy populations [21] Common in Japanese and Korean populations [22] |
| Type 3 galactosemia (OMIM 230350) |
GALE | 1p36.11 | 5 kb | 13 | Val94Met Lys257Arg Gly319Glu |
Reported in patients with generalized deficiency [23,24] Reported in African Americans with peripheral deficiency [23,24] |
| Type 4 galactosemia (OMIM 618881) |
GALM | 2p22.1 | 68 kb | 7 | Arg82* Ile99Leufs*46Trp311* Gly142Arg Arg267Gly |
Reported in Japanese patients [25,26] |
Data retrieved from ensembl.org, last accessed on 20 May 2022. The “*” is used to indicate a translational stop codon.