Diagnosis and Treatment Unit of Congenital Metabolic Diseases (UDyTEMC), Clinical University Hospital of Santiago de Compostela. National Reference Center for Metabolic Diseases (C.S.U.R.), Santiago de Compostela, Spain.
IDIS-Health Research Institute of Santiago de Compostela, Santiago de Compostela, 15704, Spain.
BMC Pediatr. 2024 Sep 30;24(1):620. doi: 10.1186/s12887-024-05074-6.
The recommended diet attitude in the recently described galactose mutarotase (GALM) deficiency is not yet established. We describe two 9-years twins who remain asymptomatic despite prolonged partial dietary liberalization from 18 months of age, after two periods of galactose-free diet. It represents the second report in Europe of GALM deficiency.
Two male monochorionic diamniotic twins were detected through newborn screening by galactosuria and increased total blood galactose. They started galactose dietary restriction with biochemical normalization. After exclusion of the three previously described types of galactosemia, a progressively galactose reintroduction was initiated. The clinical follow-up developed include neurological assessment and intelligence quotient, annual ophthalmological evaluation and biannual abdominal ultrasound; whereas the biochemical assessment comprises quarterly determinations of galactose 1-phosphate and galactosuria and annual determination of liver and renal function, 25-OH-vitamin D and calcium levels. Sanger sequencing of GALM gene was complemented by the study of gene dose using SNPs array and a protein modeling to study the conformational changes induced in GALM protein. In both siblings a novel and complete deletion of exon 4 in GALM gene was detected. Both remained asymptomatic, with normal growth and intellectual development, despite dietary liberalization. Evolutionarily, the biochemical profile in blood remained normal with intermittent galactosuria.
The absence of clinical involvement after 7 years of dietary liberalization is interesting to expand the knowledge about the recommended dietary management in this pathology.
最近描述的半乳糖差向异构酶（GALM）缺乏症的推荐饮食态度尚未确定。我们描述了两个 9 岁的双胞胎，尽管在 18 个月大后进行了两次无 galactose 饮食，仍持续部分饮食自由化，但仍无症状。这是欧洲第二例 GALM 缺乏症报告。
两名男性同卵双胎双胞胎通过尿半乳糖和总血半乳糖升高在新生儿筛查中被发现。他们开始进行 galactose 饮食限制，生化指标正常。排除了之前描述的三种半乳糖血症后，开始逐步重新引入 galactose。临床随访包括神经评估和智商、每年进行眼科评估和每两年进行一次腹部超声检查；生化评估包括每季度测定半乳糖 1-磷酸和尿半乳糖，以及每年测定肝肾功能、25-OH-维生素 D 和钙水平。GALM 基因的 Sanger 测序通过 SNP 阵列研究基因剂量和 GALM 蛋白构象变化的蛋白建模进行补充。在两个兄弟姐妹中，均检测到 GALM 基因外显子 4 的完整缺失。尽管进行了饮食自由化，但他们仍然无症状，生长和智力发育正常。从进化的角度来看，血液中的生化特征保持正常，间歇性出现半乳糖尿。
在饮食自由化 7 年后没有出现临床症状，这有助于扩展我们对该病理学中推荐饮食管理的认识。
