Case 3. A. Pedigree of the proband and parents. A filled symbol indicates the affected individual; symbols with a dot in the middle indicate carriers. GALC genotypes are given for each individual under the respective symbol. Sequence analysis performed in another laboratory identified an apparently homozygous one nucleotide deletion mutation in the proband. One copy of the mutation was identified in the proband’s mother, but her father was negative. Array CGH analysis was performed on the proband’s father to identify a suspected deletion, which was confirmed in the proband. B. GALC array CGH results for the father (top) and proband (bottom). A diagram of the GALC gene is given above the results with exon numbers indicated. Both the father and the proband have one copy of a deletion of exons 1 through 6. The deletion inherited from her father made the mutation in exon 1 inherited from her mother appear homozygous in the proband by sequence analysis.