- Aarskog-Scott syndrome
Name = PAGENAME
DiseasesDB = 29329
ICD10 = ICD10|Q|87|1|q|80
ICD9 = ICD9|759.89
OMIM = 100050
Aarskog-Scott syndrome is an
inherited diseasecharacterized by short stature, facial abnormalities, skeletal and genital anomalies.
The Aarskog-Scott syndrome (AAS) is also known as the Aarskog syndrome, faciodigitogenital syndrome, shawl scrotum syndrome and faciogenital dysplasia.
Aarskog-Scott syndrome is transmitted in an
X-linked recessivemanner. The sons of female carriers are at 50% risk of being affected with the syndrome. The daughters of female carriers are at 50% risk of being carriers themselves. Females may have mild manifestations of the syndrome. The syndrome is caused by mutationin a genecalled FGDY1in band p11.21 on the X chromosome.
The syndrome is named for Dagfinn Aarskog, a Norwegian pediatrician and human geneticist who first described it in 1970, [cite journal |author=Aarskog D |title=A familial syndrome of short stature associated with facial dysplasia and genital anomalies |journal=J. Pediatr. |volume=77 |issue=5 |pages=856–61 |year=1970 |pmid=5504078 |doi=] and for Charles I. Scott, Jr., an American medical geneticist who independently described the syndrome in 1971. [cite journal |author=Scott CI |title=Unusual facies, joint hypermobility, genital anomaly and short stature: a new dysmorphic syndrome |journal=Birth Defects Orig. Artic. Ser. |volume=7 |issue=6 |pages=240–6 |year=1971 |pmid=5173168 |doi=]
The Aarskog-Scott syndrome is a disorder with short stature,
hypertelorism, downslanting palpebral fissures, anteverted nostrils, joint laxity, shawl scrotum, and mental retardation. The physical phenotypevaries with age and postpuberal males may have only minor remnant manifestations of the prepuberal phenotype.
** mild to moderate short stature evident by 1-3 years of age
** delayed adolescent growth spurt
** slight (dull normal) to moderate mental deficiency
** hyperactivity and attention deficit
** social performance usually good
** rounded face
** wide-set eyes (
** droopy eyelids (
** downslanting eye slits (
** small nose with nostrils tipped forward (anteverted)
** underdeveloped mid-portion of the face (
** wide groove above the upper lip (broad
** crease below the lower lip
** delayed eruption of
** top portion (upper helix) of the ear folded over slightly
*Hands and feet
** small, broad hands and feet
** short fingers and toes (
** in-curving of the 5th finger (clinodactyly)
** mild webbing between the fingers and toes
** single transverse "
simian crease" in palm
** broad thumbs and big toes
** short neck
** webbing of sides of the neck
pectus excavatum(sunken chest)
** undescended testicles
Genetic testingmay be available for mutations in the FGDY1 gene. Genetic counselingis indicated for individuals or families who may carry this condition, as there are overlapping features with Fetal alcohol syndrome. [CDC. (2004). "Fetal Alcohol Syndrome: Guidelines for Referral and Diagnosis". Can be downloaded at http://www.cdc.gov/fas/faspub.htm]
Surgerymay be required to correct some of the anomalies, and orthodontictreatment may be used to correct some of the facial abnormalities. Trials of growth hormonehave not been effective to treat short stature in this disorder.
Mild degrees of mental slowness may be present, but affected children usually have good social skills. Some males may exhibit reduced fertility.
Some recent findings have included cystic changes in the brain and generalized
seizures Fact|date=February 2008 . There may be difficulty growing in the first year of life in up to one-third of cases. Misaligned teeth may require orthodontic correction. An undescended testicle will require surgery.
The Aarskog-Scott syndrome is due to mutation in the
FGD1gene. FGD1 encodes a guanine nucleotide exchange factor(GEF) that specifically activates Cdc42, a member of the Rho (Ras homology) family of the p21 GTPases. By activating Cdc42, FGD1 proteinstimulates fibroblasts to form filopodia, cytoskeletal elements involved in cellular signaling, adhesion, and migration. Through Cdc42, FGD1 protein also activates the c-Jun N-terminal kinase(JNK) signaling cascade, a pathway that regulates cell growth, apoptosis, and cellular differentiation.
Within the developing mouse skeleton, FGD1 protein is expressed in precartilaginous mesenchymal condensations, the
perichondriumand periosteum, proliferating chondrocytes, and osteoblasts. These results suggest that FGD1 signaling may play a role in the biology of several different skeletal cell types including mesenchymal prechondrocytes, chondrocytes, and osteoblasts. The characterization of the spatiotemporal pattern of FGD1 expression in mouse embryos has provided important clues to the understanding of the pathogenesisof Aarskog-Scott syndrome.
It appears likely that the primary defect in Aarskog-Scott syndrome is an abnormality of FGD1/Cdc42 signaling resulting in anomalous
embryonic developmentand abnormal endochondral and intramembranous bone formation.
* Kenneth Lyons Jones: "Smith's Recognizable Patterns of Human Malformation", 6th Edition (2005), WB Saunders, Philadelphia ISBN 072162359X
* [http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=305400 Faciogenital Dysplasia (Aarskog-Scott syndrome)] ,detailed up-to-date information in
OMIM(Online Mendelian Inheritance in Man)
* [http://health.allrefer.com/health/aarskog-syndrome-info.html Images of clinical features of Aarskog-Scott syndrome]
* [http://pedbase.org/a/aarskog-syndrome/ Pediatric Database
* The [http://www.magicfoundation.org MAGIC Foundation for Children's Growth] is a support group
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