Abstract
Titin (
TTN
) is a large gene with 363 exons that encodes a large abundant protein (longest known polypeptide in nature) that is expressed in cardiac and skeletal muscles.
TTN
has an important role in the sarcomere organization, assembly of muscles, transmission of the force at the Z-line, passive myocyte stiffness, and resting tension maintenance in the I-band region. Mutation in extreme C terminus of
TTN
, situated at the end of M-band of the
TTN
in chromosome 2q31, results in tibial muscular dystrophy (TMD), also called Udd Distal Myopathy, which is an autosomal dominant distal myopathy. In this article, we report a novel mutation in
TTN
gene in a Saudi patient with bilateral facial weakness and scapular winging. This report adds to the literature a heterozygous missense variant c.85652C>G, p.(Pro28551Arg) in
TTN
gene, which may be related to genes that cause the disease, but more case validation is needed. The novel mutation described in the present study widened the genetic spectrum of
TTN
-associated diseases, which may benefit studies addressing this disease in the future.