Compound heterozygous mutations in tripeptidyl peptidase 1 cause rare autosomal recessive spinocerebellar ataxia type 7: A case report

Figure 1 Cranial magnetic resonance imaging findings of spinocerebellar ataxia recessive type 7. A: Cranial magnetic resonance imaging (MRI) T1-weighted sequence cross-sectional image shows obvious cerebellar atrophy (orange arrow); B: Cranial MRI T2-weighted sequence sagittal image shows obvious cerebellar atrophy, deepening sulcus widening, and enlarged cerebral cistern (orange arrow).

Figure 2 Gene sequencing chromatograms. Compound heterozygous variants in the patient, tripeptidyl peptidase 1 (TPP1): c.1468G>A and c.1417G>A (blue arrow). Heterozygous variant TPP1: c.1468G>A (orange arrow) with wild-type TPP1, (c.1417G purple arrow) in the father. Heterozygous variant TPP1: c.1417G>A (blue arrow) with wild-type TPP1 (c.1468G green arrow) in the mother. Heterozygous variant TPP1: c.1417G>A (blue arrow) with wild-type TPP1 (c.1468G green arrow) in the younger brother. TPP1: Tripeptidyl peptidase 1.

Figure 3 Family pedigree. Black shading represents c.1417G>A and gray shading represents c.1468G>A. ‘wt’ denotes wild-type.