• 대한유전성대사질환학회지
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• 제16권3호
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• pp.135-140
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• 2016

Purpose: Galactose is metabolized to galactose-1-phosphate by galactokinase (GALK), galactose-1-phosphate uridyltransferase (GALT) and UDP-galactose-4-epimerase (GALE), and galactosemia occurs when each enzyme is deficient. In Korea, unlike foreign countries, classic galactosemia is rare and transient galactosemia due to GALK hyperactivity is reported, but studies on frequency, clinical significance, and genetic variation are lacking. In this study, we analyzed the clinical characteristics of patients with galactosemia due to GALK hyperactivity. Methods: We investigated 85 patients who had an elevated galactose level in the neonatal screening test without deficiency of enzymes at Department of Pediatrics, Seoul & Bucheon Soonchunhyang University Hospital from January 2008 to June 2016. We investigated the level of galactose, galactose-1-phosphate, GALK and duration of galactose normalization, and analyzed the correlation between GALK elevation and galactose, galactose-1-phosphate and duration of galactose normalization. And the levels of galactose, galactose-1-phosphate, and duration of galactose normalization were compared between the galactose-free formula feeding group and non-feeding group. Results: Mean age of visit was $26.7{\pm}16.1days$. Duration of galactose normalization was $35.3{\pm}20.5days$. Mean galactose level was $18.5{\pm}7.3mg/dL$ in the neonatal screening and follow-up galactose level in serum was $2.3{\pm}5.4mg/dL$. The mean value of galactose-1-phosphate was $6.0{\pm}4.7mg/dL$ and the mean GALK level was $3.84{\pm}1.28{\mu}mol/Hr/gHb$. There was no significant correlation between GALK levels and galactose levels in the neonatal screening test (P=0.351), and we analyzed the correlation between GALK levels and follow-up galactose levels in serum, there was no significant correlation (P=0.101). There was a significant correlation between GALK levels and galactose-1-phosphate (P=0.015), and the correlation between GALK levels and duration of galactose normalization was not statistically significant (P=0.176). 49% of the patients were fed galactose-free formula, and 45% were not. Galactose and galactose-1-phosphate levels in the neonatal screening test were statistically significantly higher (P=0.004, 0.034) in using galactose-free formula group. Duration of galactose normalization was not related to the use of galactose-free formula (P=0.266, 0.249). Conclusion: Galactosemia due to GALK hyperactivity seems to be a temporary phenomenon and may not require galactose restriction. More research is needed on the role of the nuclear protein, racial traits and genetic variations in Korean patients.

• Clinical and Experimental Pediatrics
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• 제46권5호
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• pp.440-446
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• 2003

목 적 : 갈락토스혈증은 유전성 대사 질환으로 상염색체 열성으로 유전되며 대표적으로 세 효소의 결핍에 의거하며 임상적 양상은 갈락토스에 대해 노출되면서 증상이 나타난다. 첫째는 GALT 결핍증, 둘째는 GALK 결핍증이고, 셋째는 GALE 결핍증이다. 현재 우리 나라에서 출생 후 갈락토스혈증에 대한 신생아 선별검사를 시행하고 있다. 우리 나라의 갈락토스혈증의 양상에 대해 알아보기 위해 저자들은 신생아기에 시행한 선별검사에서 이상소견을 보여 정밀검사를 시행하여 진단된 갈락토스혈증 환자에 대해 보고하는 바이다. 방 법: 신생아 선별검사에서 이상소견을 보여 생후 1개월에 순천향대학병원 소아과에서 정밀검사를 시행하여 갈락토스혈증이 확진된 환아들의 외래 및 입원 기록을 후향적으로 검토하였다. 내원 당시 갈락토스혈증을 확진하기 위해 갈락토스를 효소비색법과 형광측정법으로 측정하였고, 형광측정법으로 galactose-1-phosphate를 측정하였다. 적혈구 내의 GALK, GALT, GALE의 활성도, 그리고 galactose-1-phosphate를 동위원소 검사로 측정하였으며 Beutler 법을 시행하였다. 진단된 환아들에서는 유당제거 식이를 투여하면서 갈락토스와 galactose-1-phosphate를 추적검사 하였으며 의심되는 효소에 대한 추적 검사도 시행하였다. 결 과: 갈락토스혈증으로 확진받은 환아들은 총 10명이었고 그 중 남아가 6명, 여아가 4명이였다. 10명 중 GALK 결핍증이 2명, GALT 결핍증이 2명 그리고 GALE 결핍증이 6명으로 GALE 결핍증이 가장 많았다. 2명에서 GALK 결핍증이 진단되었으며 GALT와 GALE은 두 환아 모두에서 정상이면서 GALK가 각각 0.7, 8.02 nmol/min/g Hb로 감소되어 있어 GALK 결핍증으로 진단하였다. 1명의 환아의 경우 GALK가 심하게 감소되어 있었으며 2번 환아의 경우 2세와 3세에 추적 검사한 GALK가 각각 16.7, 16.8 nmol/min/g Hb로 1세 이후의 정상치인 20-30 보다 낮았으며 감소 정도로 보아 보인자로 생각되었다. GALT 결핍증의 경우 2명의 환아에서는 적혈구 내의 GALT의 활성도가 각각 6.7, $8.6{\mu}L/hr/g$ Hb로 정상보다 감소되어 있어 GALT 결핍증으로 진단하였으며 두 환아 모두 DNA분석에서 Duarte 2/G(galactosemia)의 유전형을 갖는 Duarte 2 variant galactosemia로 진단되었다. GALE 결핍증이 7명으로 가장 많았으며 GALE의 활성도는 6명 모두에서 정상보다 감소되어 있었다. 이들 중 3명은 적혈구 내의 GALE의 활성도가 진단시 각각 14.9, 9.2 $8.6{\mu}L/hr/g$ Hb이었고 추적 검사한 GALE의 활성도는 각각 14.8, 12.7, $12.21{\mu}L/hr/g$ Hb로 이들의 감소정도로 보아 GALE 결핍증 중 경증 또는 보인자로 생각되었다. 1명은 진단시 및 추적 검사한 GALE의 활성도가 각각 2.9, $6.46{\mu}L/hr/g$ Hb로 감소 정도로 보아 homozygote state로 추정되었다. 또한 다른 1명은 GALE의 활성도가 $6.8{\mu}L/hr/g$ Hb로 감소 정도로 보아 homozygote state로 추정되나 앞으로 추적 검사가 필요할 것으로 사료된다. 그 외에 4명의 환아들의 경우 효소의 결핍에 의한 갈락토스혈증이 아니라 GALK의 과다반응에 의해 갈락토스가 증가하는 소견을 보였다. 그러므로 갈락토스 농도가 증가하였을 때 GALK 과다반응의 경우를 감별해야한다. 결 론 : 본 연구의 경우 임상적으로 증상이 있었던 경우는 없었으며 GALE 결핍증이 가장 많았고 GALT 결핍증 환아들은 모두 보인자였다. 또한 유당 제거 식이 후 갈락토스와 galactose-1-phosphate는 정상 범위를 유지하였다. 신생아 선별검사를 통해 갈락토스혈증이 의심되는 경우 정밀검사를 통해 확진을 하여 갈락토스혈증이 어떤 병형인가를 알아내는 것이 예후에 중요하며 조기 치료를 하는 것이 필요하다.

• 통합자연과학논문집
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• 제8권4호
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• pp.267-272
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• 2015

Galactosemia is a potentially lethal disorder caused by the deficiency of the enzyme galactose-1-phosphate uridyltransferase (GALT) within the Leloir pathway. Galactokinase (GALK) is the enzyme in Leloir pathway which converts ${\alpha}$-D galactose to galactose 1-phosphate. The elevated level of galactose-1-phosphate, the product of GALK plays a major role in Galactosemia. Therefore the inhibition of GALK is a novel therapy for this disorder. Hence in the present study, we performed molecular docking of twenty inhibitors with different activity against galactokinase into the active site of galactokinase enzyme. The binding mode of these inhibitors was obtained using Surflex dock program interfaced in Sybyl-X2.0. The residues such as SER141, TYR109, ARG105, ARG228, TYR106, GLY346, GLY136, ASP86, ASP186 and SER142 found to interact with inhibitors.

• 대한유전성대사질환학회지
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• 제13권2호
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• pp.89-97
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• 2013

Purpose: We retrospectively investigated individuals who hadbeen identified by neonatal screening as potential galactosemia patients to determine the etiology of galactosemia. Methods: One hundred fifty-three patients referred to Korea Genetics Research Center due to high galactose level detected by neonatal screening test between February 2005 and May 2013 were examined. Galactose and galactose-1-phosphate levels were measured by using a fluoro metric microplate reader. Lactose free diet was initiated immediately after confirmed by urine Clinitest. If reducing sugar was negative, we employed abdominal sonogram and echocardiogram to check for possible porto-systemic shunt. Results: Fifteen patients were diagnosed with galactosemia. One patient had galactokinase (GALK) deficiency; four had UDP galactose-4-epimerase (GALE) deficiency; two had citrin deficiency; and four had porto-systemic shunt. Two had unknown causes of galactosemia. Conclusion: In addition to genetic defects of GALT, GALK and GALE, citrin deficiency or porto-systemic shunt could also cause galactosemia. It is crucial to carry out differential diagnosis to determine the cause of galactosemia.

• 대한유전성대사질환학회지
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• 제23권2호
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• pp.15-20
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• 2023

Galactosemia is an inborn error disorder of carbohydrate metabolism, caused by metabolic disturbances at various stages of the Leloir pathway. In patients with galactosemia, accurate diagnosis and appropriate care are essential to avoid complications and unnecessary treatments. And a careful differential diagnosis of the type of galactosemia is crucial. Even with an appropriate galactose-restricted diet, long-term complications may occur, especially in patients with classic galactosemia. So new treatment options are being developed. In this review, we will review the new symptoms of each subtype that have been reported recently and GALM (Galactose mutarotase) deficiency, a new form of galactosemia, and treatment policies according to recent guidelines.

• 대한유전성대사질환학회지
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• 제13권2호
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• pp.126-130
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• 2013

Galactosemia is a metabolic disorder inherited by the recessive autosome, and appears by the deficiency of one enzyme out of GALT (Galactose-1-Phosphate Uridyltransferase), GALK (galactokinase), and GALE (epimerase) enzymes, among which the GALT deficiency disease is denominated as classical galactosemia and known to have symptoms such as severe nausea, jaundice, hepatomegaly, sucking difficulty and so on. We report the case of a 16-day-old female baby with the new p.A101D mutation together with p.N413d in the GALT gene analysis found in the neonatal screening test and diagnosed to have galactosemia by the GALT deficiency through the enzyme analysis. For the prognosis prediction, the treatment, the genetic counseling and the prenatal diagnosis of the patients, more detailed genetic diagnosis is required by performing GALT gene analysis, and it is deemed to be necessary to analyze the correlation between the phenotype and the genotype of the domestic galactosemia patients.

• Journal of Animal Science and Technology
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• 제56권7호
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• pp.23.1-23.7
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• 2014

Background: Scanning of the genome for selection signatures between breeds may play important role in understanding the underlie causes for observable phenotypic variations. The discovery of high density single nucleotide polymorphisms (SNPs) provide a useful starting point to perform genome-wide scan in pig populations in order to identify loci/candidate genes underlie phenotypic variation in pig breeds and facilitate genetic improvement programs. However, prior to this study genomic region under selection in commercially selected Berkshire and Korean native pig breeds has never been detected using high density SNP markers. To this end, we have genotyped 45 animals using Porcine SNP60 chip to detect selection signatures in the genome of the two breeds by using the $F_{ST}$ approach. Results: In the comparison of Berkshire and KNP breeds using the FDIST approach, a total of 1108 outlier loci (3.48%) were significantly different from zero at 99% confidence level with 870 of the outlier SNPs displaying high level of genetic differentiation ($F_{ST}{\geq}0.490$). The identified candidate genes were involved in a wide array of biological processes and molecular functions. Results revealed that 19 candidate genes were enriched in phosphate metabolism (GO: 0006796; ADCK1, ACYP1, CAMK2D, CDK13, CDK13, ERN1, GALK2, INPP1; MAK, MAP2K5, MAP3K1, MAPK14, P14KB, PIK3C3, PRKC1, PTPRK, RNASEL, THBS1, BRAF, VRK1). We have identified a set of candidate genes under selection and have known to be involved in growth, size and pork quality (CART, AGL, CF7L2, MAP2K5, DLK1, GLI3, CA3 and MC3R), ear morphology and size (HMGA2 and SOX5) stress response (ATF2, MSRB3, TMTC3 and SCAF8) and immune response (HCST and RYR1). Conclusions: Some of the genes may be used to facilitate genetic improvement programs. Our results also provide insights for better understanding of the process and influence of breed development on the pattern of genetic variations.