Canavan Disease: Clinical and Laboratory Profile from Southern Part of India

Canavan disease (CD) is an autosomal recessively inherited leukodystrophy. It affects one in 6,400 to 13,500 people in the Jewish population. However, prevalence and presentation of the disease in India is largely unknown; hence, we are reporting this series.

This is a retrospective chart review in a tertiary care hospital from January 2015 to March 2020. CD was confirmed by elevated N- acetyl aspartate (NAA) levels in urinary gas chromatography and mass spectrometry (GCMS)/increased NAA peak in magnetic resonance spectroscopy (MRS) and/or detection of mutations. The data was extracted in a predesigned proforma and analyzed.

We had 12 children with mean age at presentation being 6.8 months (range 3 months to 10 months.). Males were more commonly affected (83.3%, n = 10). Ten children (83.3%) were born out of consanguineous parentage. All of them had visual impairment and pyramidal signs. Seizures were noted in five (42%) children. Normal head size in three (25%) and microcephaly in two (16.66%) cases were noted. Magnetic resonance imaging (MRI) revealed signal changes with bilateral symmetric T2W white matter (WM) hyperintensities in subcortical U fibers in all cases. MRS was done in ten children, all of which showed increased NAA peak. Increased level of NAA in urinary GCMS was noted in six out of eight children. Six cases had homozygous pathogenic variants in ASPA gene. Antenatal diagnosis helped in prevention of recurrence in three families.

Urinary NAA and MRS showing NAA peak are useful in diagnosis of CD. Macrocephaly is not a necessary finding to diagnose CD. Early diagnosis helps in genetic counseling and prevention of subsequent conceptions.