Identify the type of mutation shown Original Sequence: GGC TAC ATG GAA Mutated Sequence: GGC TAA TGG AA deletion

Cx is a member of the family of connexin genes that encode the proteins of gap junction intercellular channels. Cx proteins in one cell form hemi-channels in the plasma membrane. Hemi-channels in adjacent cells dock to form complete intercellular channels through which ions and small molecules diffuse from cell to cell. Distinct Cx mutations were identified in three different families, F1, F2 and F3, affected by the same disease. To study their functional properties, normal (wild type, wt) and mutant (m) Cx proteins were expressed in cultured cells. Translation of the proteins was checked (Fig. 3). A extracellular EC 1 SM TM 1 membrane 2 3 4 F10 intracellular N F2 EC 2 F3 oricand c B 42 kDa C 42 kDa 35 kDa Control wt m-F1 m-F2 PM C PM C PM C PM C Western blot anti-Cx Control wt PM C m-F1 PM C PM C = Metabolically labelled m-F2 PM C m-F3 PM C m-F3 PM C WSEY Fig. 3 mont (A). Membrane topology of Cx protein indicating positions of mutations. Cx is an integral membrane protein with 4…

Discuss the following mutations with reference to specific genetic disorders: i) Faulty DNA repair; ii) Gain-of-function; and iii) Trinucleotide repeats.  Give steps for each mutations.

Explain the Mutations at the Huntington disease locus are caused by an expansion of a trinucleotide repeat SSR in a coding region.