Intellectual disability is a neurodevelopmental disorder in which intellectual functioning is affected and discrepancies are present in at least two adaptive behaviors (American Psychiatric Association 2000). It develops before age 18 and intelligence quotient is below 70 of affected person. Its prevalence is approximately 1% to 3%.in all over the world. Mostly its cases are heterogenic in nature. Although it is present in all parts of the world, but developing countries are affected more, where standard of living is low and consanguinity is more common. It may be due to the prevailing environment in cultures where socioeconomic status of people is not good. Two main reasons of ID are genomic and external factors like environment. In developed countries, it is mostly due to genetic factors, but the underlying cause is not determined in most cases. Genetic factors can be chromosomal aberrations, X-linked, autosomal recessive or autosomal dominant or de novo mutations. In contrast to past few decades, now it is assumed that autosomal-recessive forms of non-syndromic MR (NS-ARMR) are more prevailing than X-linked mental retardation. Although these autosomal recessive gene abnormalities are the common culprits in intellectual disability, yet there is very little research about them. In present study five families from various areas of Khuzdar were enrolled. These families have two or more members suffering from intellectual disability. A complete medical history was obtained to minimize likelihood of other problems like environmental issues. Then sequencing of TRAPPC9 gene is performed and results show variants in three families. Family 1 and 2 showed synonymous variant in exon 11 of TRAPPC9 gene at c.1692 C>T (p.Asn564Asn), where nucleotide sequence changes from AAC>AAT but amino acid does not change (rs12549048). Family 1 also showed missense mutation in exon 19, c.2797 G>A (p.Gly933Ser), where change from GGT>AGT results in substitution of Serine instead of Glycine (rs114949291). Family 5 show missense changes in exon 18 of this gene, at c.2647 G>A (p.Glu883Lys), where change from GAA>AAA results in Lysine instead of Glutamic acid (rs1202087896).