Other clinical manifestations include growth retardation, renal abnormalities, mental retardation and voice changes. Chronic cholestasis can lead to malabsorption of fat soluble vitamins due to lack of bile salts. Vitamin D deficiency can result from this malabsorption as well being due to a deficiency of 25-hydroxylation secondary to destruction of liver parenchyma. Diagnosis of Alagille syndrome is made by liver biopsy and histological examination of the interlobular bile ducts. This syndrome can be transmitted in an autosomal dominant mode.
Management includes a high energy diet with adequate protein intake.
Fat soluble vitamins may need to be supplemented. Our patient has severe demineralization and pathologic fractures due to vitamin D deficiency resulting in rickets. Provitamin D3, is a prohormone that eventually is converted to the active form of vitamin D, 1,25-dihydroxyvitamin D3. This active form increases intestinal calcium and phosphorous absorption, mobilizes calcium and phosphorous from bone to the bloodstream, and retains calcium and phosphorous through its renal effect. This renal effect moves calcium and phosphorous out of older bone and also promotes the maturation and mineralization of newly formed organic bone matrix.