Agranier Maxime, Demurger Florence, Dubourg Christele, Fromageot Jerome, Dufour Anne-Sophie Cabaret, Launay Erika, Gournay Magalie, Lefèvre Charles, Froissart Roseline, Pettazzoni Magali, Rollier Paul
Laboratory of Cytogenetics and Cell Biology, Rennes University Hospital, Rennes, France.
Bretagne Atlantique Hospital, Department of Paediatrics, Vannes, France.
BMC Pregnancy Childbirth. 2025 Jan 3;25(1):3. doi: 10.1186/s12884-024-07115-5.
Mucopolysaccharidosis type I (MPS I - IDUA gene) is a rare autosomal recessive lysosomal storage disorder. Clinical symptoms, including visceral overload, are progressive and typically begin postnatally. Descriptions of hepatosplenomegaly associated with lysosomal pathology are uncommon during the prenatal period. The most prevalent etiologies are infections, anemia, and neoplasms.
A pregnant woman at 26.5 gestational weeks was referred to our center for fetal ultrasound findings of hepatosplenomegaly, distinct facial features, and liver, spleen and thymus echogenic spots. Whole exome sequencing after amniocentesis identified two likely pathogenic IDUA gene variants (in trans), raising suspicion of a diagnosis of MPS I. MPS I was confirmed by the deficiency of α-L-iduronidase activity in amniotic cells. A medical pregnancy termination was carried out due to the severe prognosis. After termination of pregnancy, external examination of the fetus confirmed hepatosplenomegaly and coarse dysmorphic features.
Lysosomal storage diseases (LSD) are a rare cause of prenatal hepatosplenomegaly, but this has not been described in MPS I according to our literature search. The genetic variants identified in this case prompted early diagnosis through genome-wide studies. This rare presentation of MPS I highlights the expanding role of genomic analyses in diagnosing conditions during pregnancy.
I型粘多糖贮积症（MPS I - IDUA基因）是一种罕见的常染色体隐性溶酶体贮积病。临床症状，包括内脏负荷过重，呈进行性发展，通常在出生后开始出现。产前期间，与溶酶体病理相关的肝脾肿大描述并不常见。最常见的病因是感染、贫血和肿瘤。
一名孕26.5周的孕妇因胎儿超声检查发现肝脾肿大、特殊面部特征以及肝脏、脾脏和胸腺回声斑点而转诊至我院。羊水穿刺后进行的全外显子组测序确定了两个可能致病的IDUA基因变异（反式），这增加了MPS I诊断的怀疑。羊水中α-L-艾杜糖醛酸酶活性缺乏证实了MPS I的诊断。由于预后严重，实施了人工终止妊娠。终止妊娠后，胎儿的外部检查证实存在肝脾肿大和粗糙的畸形特征。
溶酶体贮积病（LSD）是产前肝脾肿大的罕见原因，但根据我们的文献检索，MPS I中尚未有此类描述。本病例中鉴定出的基因变异通过全基因组研究促成了早期诊断。MPS I的这种罕见表现突出了基因组分析在孕期疾病诊断中日益重要的作用。
