8 months old baby with extremely high HVA values in CSF
 

Hello,
Shira is a nine- months baby girl weights 7.5 kg. She is a product of healthy non-consanguineous parents. Normal prenatal history.
She had hypertonicity and irritability from the first days of life. By the age of 3 months she developed generalized hypertonicity due to rigidity and dystonia, rest tremor that worsens with crying, bradymimia with oromandibular and- lingual dyskinesia, drooling and diaphoresis.
She is very alert, communicative, but her movement activity is significantly limited due to generalized rigidity and dystonia.
Evaluation including brain MRI, blood lactate, amino acids, urine organic acids was normal. She had transient elevation of CPK .
CSF studies revealed normal glucose, lactic acid, Biopterin 58, Neopterin 16.
CSF neurotransmitters: HVA-3523 (295-932), 5HIAA 632 (114-336), HVA/5HIAA RATIO -6.8 (1.5-3.5)
Urine HVA: HVA-109.33 mg/gr (5-19), creatinine 15 mg/dl (90-300)

Since the extremely high hva values fits nothing we are looking for a differential diagnosis.
Thanks for your help in advance...