Phenylketonuria presenting in adulthood as progressive spastic paraparesis with dementia

Abstract

A 57 year old woman living independently in the community presented with four years of progressive spastic paraparesis and dementia. An extensive evaluation for the usual causes of these diYculties was unrevealing, but her serum phenylalanine concentration was markedly elevated and genetic analysis demonstrated mutations in the phenylalanine hydroxylase gene consistent with classic phenylketonuria. A protein restricted diet was associated with improvement in her condition. Although untreated phenylketonuria is typically associated with severe neurological dysfunction beginning in early childhood, this case shows that disability may be delayed until adulthood. (J Neurol Neurosurg Psychiatry 2001;71:795-797)

Delayed diagnosis of phenylketonuria – a case report of two siblings

“…Delayed diagnosis of PKU presenting with neurological dysfunction like spastic paraparesis, dementia and mental retardation has been reported. 9,10,11,12 To the best of our knowledge this is the first ever case report, with simultaneous, delayed adult diagnosis of PKU in two members of the same family. Significant difference in phenotype is well documented in untreated classical PKU patients with only subtle learning difficulties in 10% of patients.…”

Musty odour, mental retardation, and spastic paraplegia revealing phenylketonuria in adulthood

“…When untreated, PKU may become apparent during adulthood and a few patients have been reported to develop late spastic paraparesis or tetraparesis with or without cognitive deterioration [7]. Reversible spastic paraparesis can occur in patients with known PKU after stopping and reintroducing a phenylalanine diet [8].…”

Phenylketonuria (PKU) – A Success Story

“…He was drinking copious amounts of "Diet Coke", "Googled" aspartame and asked his neurologist to do his phenylalanine level -it was 4500 µ mil/L (3500 off aspartame). Kasim (Kasim et al, 2001) reports a woman, with an IQ of 108, functioning normally 'till age 57, who developed slowly progressive spastic paraparesis and dementia. Her blood phenylalanine level was 2155 µmol/L.…”