Mayer-Rokitansky-Küster-Hauser syndrome (MRKH syndrome), also known as Müllerian agenesis, Müllerian aplasia, or vaginal agenesis is a congenital malformation characterized by a failure of the Müllerian duct to develop, resulting in a missing uterus and variable degrees of vaginal hypoplasia of its upper portion. Müllerian agenesis (including absence of the uterus, cervix and/or vagina) is the cause in 15% of cases of primary amenorrhoea. Because most of the vagina does not develop from the Müllerian duct, instead developing from the urogenital sinus, along with the bladder and urethra, it is present even when the Müllerian duct is completely absent. Because ovaries do not develop from the Müllerian ducts, affected people might have normal secondary sexual characteristics but are infertile due to the lack of a functional uterus. However, parenthood is possible through use of gestational surrogates. Mayer–Rokitansky–Küster–Hauser syndrome is hypothesized to be a result of autosomal dominant inheritance with incomplete penetrance and variable expressivity, which contributes to the complexity involved in identifying of the underlying mechanisms causing the condition. Because of the variance in inheritance, penetrance and expressivity patterns, MRKH is subdivided into two types: type 1, in which only the structures developing from the Müllerian duct are affected (the upper vagina, cervix, and uterus), and type 2, where the same structures are affected, but is characterized by the additional malformations of other body systems most often including the renal and skeletal systems. MRKH type 2 includes MURCS (Müllerian Renal Cervical Somite).
Chalicosis is a form of pneumoconiosis affecting the lungs or bronchioles, found chiefly among stonecutters. The disease is caused by the inhalation of fine particles of stone. The term is from Greek, χάλιξ, gravel. References


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