THE MIRACLE OF NUCLEOSIDE TREATMENT IN THYMIDINE KINASE 2 DEFICIENCY
Mutations in the gene encoding the thymidine kinase 2 enzyme affect the maintenance
and repair of mitochondria mostly in skeletal muscle cells. In this report, we present a critical case that we have been following for more than three years. The 11-month-old girl had a complaint of losing her head control. On the physical examination, the neck muscles are weak. She was able to sit with support for a short time and had a mild myopathic face. CK result was 4653mg/dL. Tandem MS was normal and hypomyelination was detected on brain MRI. Muscle biopsy was consistent with mitochondrial disease and the genetic test result was c.323C>T compound heterozygous in the TK2 gene. This girl developed respiratory failure at the age of 1.5 years, a tracheostomy was opened. At this stage, nucleoside therapy was started. 14 months after the treatment started, her tracheostomy was closed. Our patient is now 4 years old and does not need any respiratory support. She is fed by mouth. Her maximal motor capacity is walking with assistance. She is still hypotonic and there appears facial weakness. The gene encoding TK2 is located in the region of 16q22.1 and the mutations in this gene are autosomal recessive. Although there is no known effective treatment for all mitochondrial diseases deoxynucleoside therapy is life-saving in TK2-related disease, which we have succeeded in our girl. This means of therapy can be installed in all mitochondrial depletion sydromes.
Keywords: mitochondria depletion syndrome, nucleoside treatment
and repair of mitochondria mostly in skeletal muscle cells. In this report, we present a critical case that we have been following for more than three years. The 11-month-old girl had a complaint of losing her head control. On the physical examination, the neck muscles are weak. She was able to sit with support for a short time and had a mild myopathic face. CK result was 4653mg/dL. Tandem MS was normal and hypomyelination was detected on brain MRI. Muscle biopsy was consistent with mitochondrial disease and the genetic test result was c.323C>T compound heterozygous in the TK2 gene. This girl developed respiratory failure at the age of 1.5 years, a tracheostomy was opened. At this stage, nucleoside therapy was started. 14 months after the treatment started, her tracheostomy was closed. Our patient is now 4 years old and does not need any respiratory support. She is fed by mouth. Her maximal motor capacity is walking with assistance. She is still hypotonic and there appears facial weakness. The gene encoding TK2 is located in the region of 16q22.1 and the mutations in this gene are autosomal recessive. Although there is no known effective treatment for all mitochondrial diseases deoxynucleoside therapy is life-saving in TK2-related disease, which we have succeeded in our girl. This means of therapy can be installed in all mitochondrial depletion sydromes.
Keywords: mitochondria depletion syndrome, nucleoside treatment
Gokce Eser
Yeditepe University
Turkey
Ali Zeki Bedir
Yeditepe University
Turkey
Haluk Topaloglu
Yeditepe University
Turkey
The miracle of nucleoside treatment in thymidine kinase 2 deficiency
Gokce Eser
Yeditepe University Turkey
Yeditepe University Turkey