ABSTRACT
Our aim was to report two new cases of hyperlysinemia type I describing the clinical, biochemical and molecular features of the disease and the outcome of lysine restriction. Two children presented with febrile seizures followed by developmental delay, clumsiness and epilepsy. At age 2 and 8 years a biochemical and genetic diagnosis of hyperlysinemia type I was confirmed and lysine-restricted diet was started in both cases. Three years after initiation of lysine restriction, case 1 had not suffered further seizures. In case 2, tremor and dysmetria improved, but fine motor clumsiness persisted. Mild cognitive impairment was present in both patients despite dietary treatment. Laboratory studies: Plasma, urine and cerebrospinal fluid amino acid concentrations were measured by ion exchange chromatography. Mutation analysis of the AASS gene was performed by directly sequencing the PCR products. The plasma lysine values were higher than 1200 µmol/L in both cases. Additionally, an increase in dibasic aminoaciduria was observed. Lysine restriction decreased plasma lysine values and nearly normalised dibasic aminoaciduria. Mutational screening of the AASS gene revealed that case 1 was a compound heterozygote for c.2662 + 1_2662 + 5delGTAAGinsTT and c.874A>G and that case 2 was a compound heterozygote for c.976_977delCA and c.1925C>G. In conclusion, we present two children with hyperlysinemia type I and neurological impairment in which implementation of lysine-restricted diet achieved a mild improvement of symptoms but did not reverse cognitive impairment. The partial decrease of lysine concentrations and the normalisation of urine excretion of dibasic amino acids after lysine restriction further reinforce the possibility of this therapeutic intervention, although further investigations seem necessary.
Subject(s)
Hyperlysinemias/diet therapy , Hyperlysinemias/diagnosis , Amino Acid Substitution , Amino Acids/blood , Amino Acids/urine , Child , Child, Preschool , Exons , Female , Gene Order , Genotype , Humans , Hyperlysinemias/genetics , Hyperlysinemias/metabolism , Mutation , Saccharopine Dehydrogenases/geneticsABSTRACT
Arachnoid cysts are a relatively common incidental finding on neuroimaging studies of the brain. Although most cases are sporadic, there have been some reports of arachnoid cysts in several members of the same family. This report describes two additional families with three members affected in each one. Both families had members with arachnoid cysts in two consecutive generations. In one of the families, arachnoid cysts were associated with a deletion in the long arm of chromosome 16, an association not described previously. These descriptions suggest that in some cases arachnoid cysts may have a genetic basis.
