Analysis of exonic region of PCNT gene in Microcephalic Osteodysplastic Primordial Dwarfism Type II subjects

Abstract

MOPD II is an autosomal recessive disorder. It is characterised by the presence of intra uterine growth retardation as well as post natal growth retardation. The adult height is not more than 100 cm. It has been found that mutation in PCNT gene is associated with MOPD II. The cytogenetic location of this gene is 21q22.3 and it contains 47 exons. It encodes for PCNT protein which is a very large coiled scaffold protein and helps in microtubule polymerisation ensuring proper cell division. Till date 74 mutations have been identified this includes deletion, stop, frame shift and non sense mutation. The present study was carried out to analyse the exonic region of PCNT gene in Microcephalic Osteodysplastic Primordial Dwarfism Type II subjects. As it is an autosomal rescessive disorder both male and female were equally affected. The study included three subjects diagnosed with MOPD II .The DNA was extracted from whole blood and was amplified using locus specific primers. The products were sequenced using Sanger sequencing and were analysed. Total 12 variants were detected and 2 of which were pathogenic and 2 were synonymous and remaining 8 were polymorphic variants. 3 were present in exon 44 and 1 in exon 31 .These 3 variants were found to be present in all four subjects while 1 was present in only one subject. Change in nucleotide sequence may produce deleterious affect which is needed to be explored along with the complete structure of PCNT protein.