A Diagnostic Algorithm of Newborn Screening for Galactosemia

갈락토스혈증의 신생아 선별검사 후 진단 알고리즘

  • Sohn, Young Bae (Department of Medical Genetics, Ajou University Hospital, Ajou University School of Medicine)
  • 손영배 (아주대학교 의과대학 의학유전학과)
  • Published : 2015.12.25

Abstract

Classic galactosemia (OMIM #230400) is an autosomal recessive inherited metaboic disorder caused by a deficiency of the galactose-1-phosphate uridyltransferase (GALT, EC2.7.7.12) due to mutations in the GALT gene. If untreated, classic galactosemia is a potentially lethal disease presenting with poor feeding, vomiting, jaundice, liver failure, increased bleeding tendency, and septicemia leading to death within a few days after birth. Since 2006, expansion of newborn screening has been enabled the early diagnosis and early intervention of classic galactosemia in Korea. However, newborn screening, followup testing for confirmatory diagnosis and intervention for galactosemia continue to present challenges. In Korea, the prevalence of the classic galactosemia is considered relatively low compared to that of western countries. And the genotype is also clearly different from those of other population. Therefore, our own guideline for confirmatory diagnosis and intervention is needed. Here, the diagnostic algorithm for galactosemia after positive newborn screening result in Korea has been proposed. Considering the low prevalence and different mutation spectrum in Koreans, the early mutation analysis of GALT gene could be a useful tool for the accurate diagnosis and making any treatment decision.

신생아 선별검사의 확장으로, 조기에 진단되어 치료하지 않으면 치명적인 경과를 보이는 고전적 갈락토스 혈증 환자를 조기 발견하여 치료할 수 있게 되었다. 신생아 선별검사에서는 원인에 관계없이 갈락토스 대사 산물이 증가한 경우를 양성으로 판정한다. 그러나 신생아 선별검사에서 양성 판정을 받은 경우 실제 GALT 효소의 완전 결핍에 의한 고전적 갈락토스혈증 뿐만 아니라, 다른 원인에 의해 갈락토스가 증가하는 경우도 많으므로 정확한 감별진단을 위한 진단 과정이 필수적이다. 특히 우리나라를 포함한 아시아에서는 서양과 달리 고전적 갈락토스혈증의 발생률이 낮으며, 유전형이 전혀 다른 것으로 보고되고 있어, 신생아 선별검사에서 갈락토스혈증이 있는 경우 정확한 원인을 감별하는 진단 과정이 서양의 것과 차별화 될 필요가 있다. 그러나 아직 우리나라에서는 선천성 대사이상질환 신생아 선별검사에서 갈락토스혈증 양성 판정을 받은 경우 이후 확진을 위한 진단 및 치료 지침이 확립되어 있지 않은 실정이다. 이에 본 종설에서는 국내 현실을 고려하여 신생아 선별검사 양성 판정을 받은 이후 확진을 위한 적절한 진단 및 치료를 위한 지침을 제시하고자 하였다. 갈락토스혈증은 위양성의 경우, 추적검사 결과를 기다리는 적어도 2-3주 동안 모유 수유를 중단해야 한다는 점을 고려해야 한다. 최근 국내에서 다양한 선천성 질환에서 유전자 검사가 매우 활발하게 이용되고 있으므로, 갈락토스혈증의 선별검사나 생화학적 검사결과가 모호하여 추적 검사를 필요로 하는 경우, 유전자 검사를 조기에 시행하면 Duarte 변이형 갈락토스혈증과 같이 철저한 식이 제한을 필요로 하지 않는 형태의 갈락 토스혈증을 감별하는데 도움이 될 것으로 생각된다.

Keywords

Acknowledgement

Supported by : 보건복지부

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