Figure S1: (A) Pedigree of the family 1 (B) Clinical photograph of P1 (i) at 8 months of age (ii) at 1 year of age (C) Pedigree of the family 2 (D) Clinical photograph of P2 (E) Sanger validation and bi-allelic segregation analysis of the variant c.191T>C p.(Leu64Pro) in the family 1 (F) Sanger validation and bi-allelic segregation analysis of the variant c.278C>T p.(Pro93Leu) in the family 2.

Figure S2: Graphical illustration of the sequence variants identified in TRAPPC4 till date.

Table S1, Variant prioritization and filtering strategy used to analyze exome sequencing data in P1.

Table S2, List of rare exonic homozygous/hemizygous variants in genes with known OMIM phenotype observed in P1. The variant in the proband is highlighted.

Table S3, Variant prioritization and filtering strategy used to analyze exome sequencing data of P3.

Table S4, List of rare exonic homozygous/hemizygous variants in genes with known OMIM phenotype observed in P3. The variant in the proband is highlighted.

Table S5: In silico prediction scores for the variants observed in the current study