Erection was pharmacologically induced in 50 Jewish Caucasian patients who had been evaluated for erectile dysfunction (ED) (average age 47±14y). Patients with penis abnormalities or whose ED could be attributed to more than one psychological origin were omitted from the study. A review published in the 2007 issue of BJU International showed the average erect penis length to be 14–16 cm (5.5–6.3 in) and girth to be 12–13 cm (4.7–5.1 in). The paper compared results of twelve studies conducted on different populations in several countries. Various methods of measurements were included in the review. A 2015 study by BJU International concluded the average erect penis length to be 13.12 cm (5.16 inches). A 2013 study of 253 men from Tanzania found that the average erect penis length of Tanzanian males was 13.12 cm (5.17 inches)
An Indian study (published in 2007) of 301 men ages 18 to 60 published in the International Journal of Impotence Research found flaccid, stretched and erect length to be 8.21 cm (3.23 in), 10.88 cm (4.28 in) and 13.01 cm (5.12 in), respectively. A Korean study (published in 1971) of 702 men ages 21 to 31 identified the average erect penis length to be 12.70 cm (5.00 in). Another study (from 1998) of 150 Koreans found the average erect penis length to be 13.42 cm (5.28 in). The most recent study (published in 2016) of 248 Korean men identified the average erect penis length to be 13.53 cm (5.33 in).
Muscular dystrophies (MD) are a genetically and clinically heterogeneous group of rare neuromuscular diseases that cause progressive weakness and breakdown of skeletal muscles over time. The disorders differ as to which muscles are primarily affected, the degree of weakness, how fast they worsen, and when symptoms begin. Some types are also associated with problems in other organs.Over 30 different disorders are classified as muscular dystrophies. Of those, Duchenne muscular dystrophy (DMD) accounts for approximately 50% of cases and affects males beginning around the age of four. Other relatively common muscular dystrophies include Becker muscular dystrophy, facioscapulohumeral muscular dystrophy, and myotonic dystrophy, whereas limb–girdle muscular dystrophy and congenital muscular dystrophy are themselves groups of several – usually ultrarare – genetic disorders. Muscular dystrophies are caused by mutations in genes, usually those involved in making muscle proteins. These mutations are either inherited from parents or may occur spontaneously during early development. Muscular dystrophies may be X-linked recessive, autosomal recessive, or autosomal dominant. Diagnosis often involves blood tests and genetic testing.There is no cure for any disorder from the muscular dystrophy group. Several drugs designed to address the root cause are under development, including gene therapy (Microdystrophin), and antisense drugs (Ataluren, Eteplirsen etc.). Other medications used include corticosteroids (Deflazacort), calcium channel blockers (Diltiazem) to slow skeletal and cardiac muscle degeneration, anticonvulsants to control seizures and some muscle activity, and immunosuppressants (Vamorolone) to delay damage to dying muscle cells.