CONGENITAL DISORDER OF GLYCOSYRATION TYPE 1B (CDG-1B SYNDROME, PHOSPHOMANNOISOMERASE DEFICIENCY): A CLINICAL CASE

Abstract

A clinical case of my own observation of a boy A., aged 1 year and 10 months, with the diagnosis: congenital glycosylation disorder type 1b (CDG 1b syndrome, phosphomannoisomerase deficiency) is presented. The writing of this article is due to the difficulties of diagnosis, which are associated with the multisystemic clinical manifestations in the form of rather non-specific pathological conditions and the lack of information about this rare pathology. Congenital glycosylation defects are a group of genetically determined diseases in which the synthesis or attachment of glycans to glycoproteins and glycolipids is violated, as well as the formation of glycosylphosphatidylinositol. More than 130 congenital defects of glycosylation are known. According to literature data, in case of congenital glycosylation defects in newborns and older children, life-threatening changes in the body are observed, which include disorders on the part of all organs and systems that contribute to disorders of physical and neuropsychological development. Recently, more and more cases of the debut of congenital glycosylation defects have been described immediately after birth in the form of a syndrome of respiratory disorders; intracranial hemorrhages in full-term newborns; long-term dysfunction of the gastrointestinal tract; life-threatening bacterial infections. The absence of clear, specific clinical manifestations of the disease leads to untimely recognition and treatment of the disease in children after birth and contributes to the violation of their development. The child's final diagnosis is determined by the results of a molecular genetic examination: exome sequencing: a heterozygous carrier of the EXTL3, MFSD8 genes takes place here. A conclusion was made about the need for dynamic observation of the boy by a pediatrician and geneticist in order to monitor physical and neuropsychological development.