She was finally diagnosed with HDLS, as confirmed by genetic analyses, which revealed a heterozygous mutation (c.2552T>C) in exon 19 of the CSF-1R gene on chromosome 5, resulting in an amino acid substitution of leucine (L) to proline (P) at codon position 851 (p.L851P). The gene discussed is CSF1R; the disease is Hereditary diffuse leukoencephalopathy with axonal spheroids and pigmented glia.