The Discovery of GALM Deficiency (Type IV Galactosemia) and Newborn Screening System for Galactosemia in Japan

Atsuo Kikuchi; Yoichi Wada; Toshihiro Ohura; Shigeo Kure

doi:10.3390/ijns7040068

The Discovery of GALM Deficiency (Type IV Galactosemia) and Newborn Screening System for Galactosemia in Japan

Int J Neonatal Screen. 2021 Oct 25;7(4):68. doi: 10.3390/ijns7040068.

Authors

Atsuo Kikuchi¹, Yoichi Wada¹, Toshihiro Ohura², Shigeo Kure^{1

3}

Affiliations

¹ Department of Pediatrics, Tohoku University School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan.
² Division of Clinical Laboratory, Sendai City Hospital, 1-1-1, Asuto-Nagamachi, Taihaku-ku, Sendai 982-8502, Japan.
³ Tohoku Medical Megabank Organization, Tohoku University, 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8573, Japan.

Abstract

The Leloir pathway, which consists of highly conserved enzymes, metabolizes galactose. Deficits in three enzymes in this pathway, namely galactose-1-phosphate uridylyltransferase (GALT), galactokinase (GALK1), and UDP-galactose-4'-epimerase (GALE), are associated with genetic galactosemia. We recently identified patients with galactosemia and biallelic variants in GALM, encoding galactose epimerase (GALM), an enzyme that is directly upstream of GALK1. GALM deficiency was subsequently designated as type IV galactosemia. Currently, all the published patients with biallelic GALM variants were found through newborn screening in Japan. Here, we review GALM deficiency and describe how we discovered this relatively mild but not rare disease through the newborn screening system in Japan.

Keywords: GALM; GALM deficiency; galactosemia; neonatal screening; newborn screening.

Publication types

Review

Grants and funding

Not applicable./Takeda Science Foundation