The Introducing An infantile form of GM ۱ gangliosidosis without organomegaly

GM۱ gangliosidosis is an inherited disorder that progressively destroys nervous system in the brain and spinal cord. researchers classify this condition into three major types based on the age at which signs and symptoms first appear. The signs and symptoms of the most severe form of GM۱ gangliosidosis, called type I or the infantile form, usually become apparent by the age of ۶ months. These patients develop an enlarged liver and spleen (hepatosplenomegaly), seizures and eventually lose the skills they had previously acquired. We introduce a ۱۷ month old girl with regression since ۹ months ago when she was a ۸ month old infant , before starting the symptoms ,her development was normal and the child was able to control her head and rolls over, after a short course of viral infection in ۸ month old she was unable to rolling and she experienced floppiness as the first time, in order to rule out metabolic disorders, tandem mass specterometry ,venous blood gas and routine labratoary examinations including electrolytes ,liver and kidney function tests were done. All of them were normal. Brain MRI showed delayed myelination according to patients age. Filter paper evaluation for storage disoders including gaucher and niemann pick type A and B were normal and abdominal sonography revealed no organomegaly In ۱ year old, after a fever following vaccination ,She lose her ability to head control and in ۱۷ month old she experienced first unprovoked seizure as focal clonic jerks of facial muscles last more than ۲۰ minutes and generalized tonic seizures. So the patient hospitalized and work ups repeated . in this time, we repeat brain MRI and it showed apparent delayed myelination including U fibers therefore a hypomyelinatin leukoencephalopathy considered new investigations including abdominal sonography, bone marrow aspiration and whole exom sequencing performed, abdominal sonography revealed normal span of liver (۸۶ mm) and spleen (۶۲ mm) again. In bone marrow aspiration foamy cells were seen and whole xome sequencing revealed a homozygote mutation on GLB۱ gene which translates to beta galactosidase enzyme, so diagnosis of GM۱ gangliosidosis established, the parents were heterozygote for this mutation and they were cousins. We report a ۱۷ month old girl with regression since ۸ month old and hypomyelinating leukoencephalopathy in brain MRI with a definite diagnosis of infantile form of GM۱ gangliosidosis without any organomegaly, therefore according to classification it is an interesting manifestation of infantile form of disease.

کلیدواژه ها:

GM۱ Gangliosidosis ، Regression ، Organomegaly.