Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content +++ Key Points ++ Disease summary: Werner syndrome is an adult-onset genetic disorder characterized by features suggestive of accelerated aging (“segmental progeroid syndrome”) and cancer predisposition. Individuals with Werner syndrome appear to develop normally during the first decade of life. The first sign often recognized retrospectively is the lack of a growth spurt during the early teen years. Early findings (usually observed in the 20s) include loss and graying of hair, hoarseness or high-pitched voice, and scleroderma-like skin changes, followed by bilateral ocular cataracts, type 2 diabetes mellitus, hypogonadism, skin ulcers (particularly of the ankles), and osteoporosis in the 30s. Myocardial infarction and cancer are the most common causes of death, at about age 54 years. Hereditary basis: Werner syndrome is caused by mutations in the WRN gene. The WRN gene encodes a helicase that unwinds DNA. Werner syndrome is inherited in an autosomal recessive manner. Differential diagnosis: Atypical Werner syndrome refers to a small subset of individuals with a normal WRN gene sequence, normal WRN protein, and some signs and symptoms that sufficiently overlap with the Werner syndrome such that clinicians submit these cases to the International Registry. These individuals may give a history of comparatively early age of onset and a faster rate of progression than those with typical Werner syndrome. Among this group, 4 of 26 individuals so far investigated (15%) had novel heterozygous missense mutations in LMNA, which encodes the nuclear intermediate filament lamin A/C. These mutations are N-terminal to the canonical C-terminal mutations of the classical Hutchinson-Gilford progeria syndrome (HGPS) (see later). Mandibuloacral dysplasia (MAD) is characterized by short stature; thin, hyperpigmented skin; partial alopecia, prominent eyes, beaked nose, tooth loss, small recessed chin, and short fingers. The Arg527His mutation in the C-terminal region of lamin A/C accounts for approximately 90% of the recessive MAD caused by LMNA mutations. A small subset of MAD is caused by mutations in the ZMPSTE24 gene, whose gene product is involved in the processing of lamin A. The HGPS or progeria of childhood, like Werner syndrome, affects multiple organs with presentations suggestive of accelerated aging. Newborns with HGPS usually appear normal, but profound failure to thrive occurs during the first year. Characteristic facies, partial alopecia progressing to total alopecia, loss of subcutaneous fat, stiffness of joints, bone changes, and abnormal tightness of the skin over the abdomen and upper thighs usually become apparent during the second to third year. Motor and mental development is normal. Individuals with HGPS develop severe atherosclerosis. Death usually occurs as a result of complications of cardiac or cerebrovascular disease generally between age 6 and 20 years. Average life span is approximately 13 years. About 90% of individuals with HGPS have the same p.Gly608Gly in exon 11 of the LMNA gene, a mutation that creates a cryptic splice site. Inheritance is autosomal dominant. All individuals with HGPS have a de novo mutation, although inheritance via a mosaic testicular mutation is a potential mechanism. Early-onset type 2 diabetes with ... Your Access profile is currently affiliated with '[InstitutionA]' and is in the process of switching affiliations to '[InstitutionB]'. Please click ‘Continue’ to continue the affiliation switch, otherwise click ‘Cancel’ to cancel signing in. Get Free Access Through Your Institution Learn how to see if your library subscribes to McGraw Hill Medical products. Subscribe: Institutional or Individual Sign In Username Error: Please enter User Name Password Error: Please enter Password Forgot Password? Forgot Username? Sign in via OpenAthens Sign in via Shibboleth You already have access! Please proceed to your institution's subscription. Create a free a profile for additional features.