METHEMOGLOBINEMIA WITH NEUROLOGICAL MANIFESTATIONS: A CASE OF RECESSIVE CONGENITAL METHEMOGLOBINEMIA TYPE II/ NOROLOJIK BULGULARLA BIRLIKTE OLAN METHEMOGLOBINEMI: TIP II KONJENITAL RESESIF METHEMOGLOBINEMI OLGUSU

• Published in: İstanbul Tıp Fakültesi dergisi = Journal of the Istanbul Faculty of Medicine Vol. 87; no. 1; p. 87
• Main Authors: Arslan, Mujgan, Boztepe, Kubra, Ayyildiz, Veysel Atilla, Ozbas, Halil
• Format: Journal Article
• Language: English
• Published: Istanbul University Press 01-03-2024
• Subjects: Causes of; Complications and side effects; Cyanosis; Diagnosis; Methemoglobinemia; Neurologic manifestations of general diseases; Pediatric research; Turkey
• ISSN: 1305-6433
• DOI: 10.26650/IUITFD.1284643

Congenital methemoglobinemia is a rare cause of cyanosis that is characterized by increased methemoglobin levels and caused by mutations in the cytochrome B5 reductase 3 (CYB5R3) gene resulting in deficiencies of the nicotinamide adenine dinucleotide-cytochrome b5 reductase enzyme. The congenital disease has two types: type I, in which the enzyme deficiency occurs only in the erythrocytes, and type II, in which all tissues are affected. Accordingly, cyanosis is the sole clinical manifestation in type I, whereas cyanosis is accompanied by such severe neurological findings as intellectual disability, microcephaly, generalized dystonia, and movement disorders. In this study, a case who presented with respiratory distress was found to have high methemoglobin levels and was diagnosed with type II congenital methemoglobinemia due to the presence of neurological findings was presented. The patient's treatment was adjusted, the methemoglobin level was reduced, and cyanosis regressed, but no change was observed in neurological findings. This untreatable, rare condition must be included in the differential diagnosis of patients with unexplained cyanosis and high methemoglobin levels, and genetic counseling must be provided to the family, because of its severity and 25% recurrence rate. Keywords: Methemoglobinemia, congenital, cyanosis, neurological development Konjenital methemoglobinemi, methemoglobin duzeyinde artisla seyreden, nadir siyanoz sebeplerindendir. Hastaliktan sorumlu olan nikotinamid adenin dinukleotit sitokrom b5 reduktaz enzimi eksikligine sebep olan sitokrom B5 reduktaz 3 (CYB5R3) gen mutasyonlaridir. Konjenital hastaligin iki tipi vardir; tip I'de sadece eritrositlerde enzim eksikligi gorulurken, tip II'de tum dokular etkilenir. Buna bagli olarak tip I'de siyanoz gorulen tek klinik bulgu iken tip II'de hafif siyanozun yaninda bilissel yetersizlik, mikrosefali, jeneralize distoni, hareket bozukluklari gibi ciddi norolojik bulgular eslik eder. Bu calismada, solunum sikintisi yakinmasi ile basvuran, methemoglobin duzeyi yuksek saptanan, norolojik bulgularin eslik etmesi sebebi ile tip II konjenital methemoglobinemi tanisi alan olgu sunuldu. Hastanin tedavisi duzenlendi, methemoglobin duzeyi dusuruldu, siyanoz geriledi, ancak norolojik bulgularda degisiklik gorulmedi. Tedavisi olmayan bu nadir hastalik, aciklanamayan siyanozu olup methemoglobin duzeyi yuksek saptanan hastalarin ayirici tanilari arasinda yer almali ve hastaligin siddeti ve %25 nuks orani nedeniyle aileye genetik danismanlik verilmelidir. Anahtar Kelimeler: Methemoglobinemi, konjenital, siyanoz, norolojik gelisim