Hyperphosphatasia with mental retardation syndrome
| Hyperphosphatasia with mental retardation syndrome |
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Hyperphosphatasia with mental retardation syndrome, HPMRS,[1] also known as Mabry syndrome,[2] has been described in patients recruited on four continents world-wide.[3] Mabry syndrome was confirmed [4] to represent an autosomal recessive syndrome characterized by severe mental retardation, considerably elevated serum levels of alkaline phosphatase, hypoplastic terminal phalanges, and distinct facial features that include: hypertelorism, a broad nasal bridge and a rectangular face.
Pathogenesis
While many cases of HPMRS are caused by mutations in the PIGV gene,[5] there may be genetic heterogeniety in the spectrum of Mabry syndrome as a whole.[6] PIGV is a member of the molecular pathway that synthesizes the glycosylphosphatidylinositol anchor.[7] The loss in PIGV activity results in a reduced anchoring of alkaline phosphatase to the surface membrane and an elevated alkaline phosphatase activity in the Serum (blood).
References
- ^ Mabry CC, Bautista A, Kirk RF, Dubilier LD, Braunstein H, Koepke JA (1970). "Familial hyperphosphatasia with mental retardation, seizures, and neurologic deficits". The Journal of Pediatrics.77(1):74-85.
- ^ Thompson MD, Nezarati MM, Gillessen-Kaesbach G, Meinecke P, Mendoza R, Mornet E, Brun-Heath I, Prost-Squarcioni C, Legeai-Mallet L, Munnich A, Cole DE (2010). "Hyperphosphatasia with seizures, neurologic deficit, and characteristic facial features: Five new patients with Mabry syndrome". American Journal of Medical Genetics. 152A(7):1661-1669.
- ^ Thompson MD, Killoran A, Percy ME, Nezarati M, Cole DE, Hwang PA (2006). "Hyperphosphatasia with neurologic deficit: a pyridoxine-responsive seizure disorder?". Pediatric Neurology. 34(4):303-7.
- ^ D Horn; G Schottmann, P Meinecke (2010). "Hyperphosphatasia with mental retardation, brachytelephalangy, and a distinct facial gestalt: Delineation of a recognizable syndrome". European Journal of Medical Genetics. 53(2):85-8.
- ^ Krawitz PM, Schweiger MR, Rödelsperger C, Marcelis C, Kölsch U, Meisel C, Stephani F, Kinoshita T, Murakami Y, Bauer S, Isau M, Fischer A, Dahl A, Kerick M, Hecht J, Köhler S, Jäger M, Grünhagen J, de Condor BJ, Doelken S, Brunner HG, Meinecke P, Passarge E, Thompson MD, Cole DE, Horn D, Roscioli T, Mundlos S, Robinson PN (2010). "Identity-by-descent filtering of exome sequence data identifies PIGV mutations in hyperphosphatasia mental retardation syndrome". Nature Genetics. 42(10):827-9.
- ^ Thompson MD, Roscioli T, Nezarati MM, Sweeney E, Meinecke P, Krawitz PM, Mabry CC, Horn D, Mendoza R, van Bokhoven H, Stephani F, Marcelis C, Munnich A, Brunner HB, Cole DE (2010). "Heterogeneity of Mabry syndrome: hyperphosphatasia with seizures, neurologic deficit and characteristic facial features". Vol. 60. American Society of Human Genetics. 60:892A. 892.
- ^ Ji Young Kang; Yeongjin Hong; Hisashi Ashida; Nobue Shishioh; Yoshiko Murakami; Yasu S. Morita; Yusuke Maeda; Taroh Kinoshita (2004). "PIG-V Involved in Transferring the Second Mannose in Glycosylphosphatidylinositol". The Journal of Biological Chemistry. 280(10):9489-9497.