PNPLA6 and Spastic paraplegia: The phenotypes and familial (segregation) results were consistent with Spastic paraplegia 39, autosomal recessive [OMIM: 612020], but one VUS (c.2096G>A (p.S699N) in PNPLA6 gene) is predicted inconsistently (Damaging for SIFT§ and Benign for PolyPhen_2§)