U.S. flag

An official website of the United States government

Format

Send to:

Choose Destination

Megalencephaly-polymicrogyria-polydactyly-hydrocephalus syndrome 1(MPPH1)

MedGen UID:
861164
Concept ID:
C4012727
Disease or Syndrome
Synonyms: MEGALENCEPHALY, MEGA CORPUS CALLOSUM, AND COMPLETE LACK OF MOTOR DEVELOPMENT; MEGALENCEPHALY, POLYMICROGYRIA, MEGA CORPUS CALLOSUM SYNDROME; MPPH1
 
Gene (location): PIK3R2 (19p13.11)
 
Monarch Initiative: MONDO:0011313
OMIM®: 603387

Disease characteristics

Excerpted from the GeneReview: MPPH Syndrome
MPPH (megalencephaly-postaxial polydactyly-polymicrogyria-hydrocephalus) syndrome is a developmental brain disorder characterized by megalencephaly (brain overgrowth) with the cortical malformation bilateral perisylvian polymicrogyria (BPP). At birth the occipital frontal circumference (OFC) ranges from normal to 6 standard deviations (SD) above the mean for age, sex, and gestational age; in older individuals the range is from 3 to 10 SD above the mean. A variable degree of ventriculomegaly is seen in almost all children with MPPH syndrome; nearly 50% of individuals have frank hydrocephalus. Neurologic problems associated with BPP include oromotor dysfunction (100%), epilepsy (50%), and mild-to-severe intellectual disability (100%). Postaxial hexadactyly occurs in 50% of individuals with MPPH syndrome. [from GeneReviews]
Authors:
Ghayda Mirzaa   view full author information

Additional description

From MedlinePlus Genetics
Megalencephaly-polymicrogyria-polydactyly-hydrocephalus (MPPH) syndrome is a rare disorder that primarily affects the development of the brain. Affected individuals are born with an unusually large brain and head size (megalencephaly). The head and brain continue to grow rapidly during the first 2 years of life. MPPH syndrome is also associated with a brain abnormality called bilateral perisylvian polymicrogyria (BPP). The surface of the brain normally has many ridges or folds, called gyri. In people with BPP, an area of the brain called the perisylvian region develops too many gyri, and the folds are irregular and unusually small. Other brain abnormalities, including a buildup of fluid in the brain (hydrocephalus), have also been reported in people with MPPH syndrome.

The problems with brain development cause a variety of neurological signs and symptoms. People with MPPH syndrome have delayed development and intellectual disability that ranges from mild to severe. About half of affected individuals develop recurrent seizures (epilepsy) beginning early in childhood. People with MPPH syndrome also have difficulty coordinating movements of the mouth and tongue (known as oromotor dysfunction), which leads to drooling, difficulty swallowing (dysphagia), and a delay in the production of speech (expressive language).

The brain abnormalities characteristic of MPPH syndrome are also found in a closely related condition called megalencephaly-capillary malformation syndrome (MCAP). However, MCAP includes abnormalities of small blood vessels in the skin (capillary malformations) and several other features that are not usually part of MPPH syndrome.

About half of people with MPPH syndrome have an extra finger or toe on one or more of their hands or feet (polydactyly). The polydactyly is described as postaxial because it occurs on the same side of the hand or foot as the pinky finger or little toe.  https://medlineplus.gov/genetics/condition/megalencephaly-polymicrogyria-polydactyly-hydrocephalus-syndrome

Clinical features

From HPO
Postaxial polydactyly
MedGen UID:
67394
Concept ID:
C0220697
Disease or Syndrome
Polydactyly refers to the occurrence of supernumerary digits and is the most frequent of congenital hand and foot deformities. Based on the location of the extra digits, polydactyly can be classified into preaxial, involving the thumb or great toe; postaxial, affecting the fifth digit; and central, involving the 3 central digits. Postaxial polydactyly (PAP) is further subclassified into 2 types: in type A, a well-formed extra digit articulates with the fifth or a sixth metacarpal, whereas in type B, a rudimentary, poorly developed extra digit is present (summary by Umm-e-Kalsoom et al., 2012). Genetic Heterogeneity of Postaxial Polydactyly Other forms of postaxial polydactyly type A include PAPA2 (602085) on chromosome 13q21; PAPA3 (607324) on chromosome 19p13; PAPA4 (608562) on chromosome 7q22; PAPA5 (263450) on chromosome 13q13; PAPA6 (615226), caused by mutation in the ZNF141 gene (194648) on chromosome 4p16; PAPA7 (617642), caused by mutation in the IQCE gene (617631) on chromosome 7p22; PAPA8 (618123), caused by mutation in the GLI1 gene (165220) on chromosome 12q13; PAPA9 (618219), caused by mutation in the FAM98A gene (617273) on chromosome 8q22; and PAPA10 (618498), caused by mutation in the KIAA0825 gene (617266) on chromosome 5q15.
Knee flexion contracture
MedGen UID:
98042
Concept ID:
C0409355
Finding
A type of knee joint contracture in which the knee is in a fixed bent (flexed) configuration such that it cannot be straightened actively or passively.
Atrial septal defect
MedGen UID:
6753
Concept ID:
C0018817
Congenital Abnormality
Atrial septal defect (ASD) is a congenital abnormality of the interatrial septum that enables blood flow between the left and right atria via the interatrial septum.
Ventricular septal defect
MedGen UID:
42366
Concept ID:
C0018818
Congenital Abnormality
A hole between the two bottom chambers (ventricles) of the heart. The defect is centered around the most superior aspect of the ventricular septum.
Mitral regurgitation
MedGen UID:
7670
Concept ID:
C0026266
Disease or Syndrome
An abnormality of the mitral valve characterized by insufficiency or incompetence of the mitral valve resulting in retrograde leaking of blood through the mitral valve upon ventricular contraction.
Vascular ring
MedGen UID:
65131
Concept ID:
C0221214
Congenital Abnormality
A developmental defect of the aortic arch system in which the trachea and esophagus are completely encircled by connected segments of the aortic arch and its branches. This occurs if the normal process of regression and persistence of the bilateral embryonic aortic arches fails.
Overgrowth
MedGen UID:
376550
Concept ID:
C1849265
Finding
Excessive postnatal growth which may comprise increased weight, increased length, and/or increased head circumference.
Hydrocephalus
MedGen UID:
9335
Concept ID:
C0020255
Disease or Syndrome
Hydrocephalus is an active distension of the ventricular system of the brain resulting from inadequate passage of CSF from its point of production within the cerebral ventricles to its point of absorption into the systemic circulation.
Seizure
MedGen UID:
20693
Concept ID:
C0036572
Sign or Symptom
A seizure is an intermittent abnormality of nervous system physiology characterized by a transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain.
Megalencephaly
MedGen UID:
65141
Concept ID:
C0221355
Congenital Abnormality
Diffuse enlargement of the entire cerebral hemispheres leading to macrocephaly (with or without overlying cortical dysplasia).
Polymicrogyria
MedGen UID:
78605
Concept ID:
C0266464
Congenital Abnormality
Polymicrogyria is a congenital malformation of the cerebral cortex characterized by abnormal cortical layering (lamination) and an excessive number of small gyri (folds).
Hypoplasia of the corpus callosum
MedGen UID:
138005
Concept ID:
C0344482
Congenital Abnormality
Underdevelopment of the corpus callosum.
Global developmental delay
MedGen UID:
107838
Concept ID:
C0557874
Finding
A delay in the achievement of motor or mental milestones in the domains of development of a child, including motor skills, speech and language, cognitive skills, and social and emotional skills. This term should only be used to describe children younger than five years of age.
Thick corpus callosum
MedGen UID:
371993
Concept ID:
C1835194
Finding
Increased vertical dimension of the corpus callosum. This feature can be visualized by sagittal sections on magnetic resonance tomography imaging of the brain.
Intellectual disability, profound
MedGen UID:
892508
Concept ID:
C3161330
Mental or Behavioral Dysfunction
Profound mental retardation is defined as an intelligence quotient (IQ) below 20.
Ventriculomegaly
MedGen UID:
480553
Concept ID:
C3278923
Finding
An increase in size of the ventricular system of the brain.
Pachygyria
MedGen UID:
504794
Concept ID:
CN001193
Finding
Pachygyria is a malformation of cortical development with abnormally wide gyri with sulci 1,5-3 cm apart and abnormally thick cortex measuring more than 5 mm (radiological definition). See also neuropathological definitions for 2-, 3-, and 4-layered lissencephaly.
Kyphosis
MedGen UID:
44042
Concept ID:
C0022821
Anatomical Abnormality
Exaggerated anterior convexity of the thoracic vertebral column.
Frontal bossing
MedGen UID:
67453
Concept ID:
C0221354
Congenital Abnormality
Bilateral bulging of the lateral frontal bone prominences with relative sparing of the midline.
Skeletal muscle atrophy
MedGen UID:
892680
Concept ID:
C0541794
Pathologic Function
The presence of skeletal muscular atrophy (which is also known as amyotrophy).
Axial hypotonia
MedGen UID:
342959
Concept ID:
C1853743
Finding
Muscular hypotonia (abnormally low muscle tone) affecting the musculature of the trunk.
Thoracic scoliosis
MedGen UID:
387910
Concept ID:
C1857790
Anatomical Abnormality
Macrocephaly
MedGen UID:
745757
Concept ID:
C2243051
Finding
Occipitofrontal (head) circumference greater than 97th centile compared to appropriate, age matched, sex-matched normal standards. Alternatively, a apparently increased size of the cranium.
Long palpebral fissure
MedGen UID:
340300
Concept ID:
C1849340
Finding
Distance between medial and lateral canthi is more than two standard deviations above the mean for age (objective); or, apparently increased length of the palpebral fissures.
Ptosis
MedGen UID:
2287
Concept ID:
C0005745
Disease or Syndrome
The upper eyelid margin is positioned 3 mm or more lower than usual and covers the superior portion of the iris (objective); or, the upper lid margin obscures at least part of the pupil (subjective).
Blindness
MedGen UID:
99138
Concept ID:
C0456909
Disease or Syndrome
Blindness is the condition of lacking visual perception defined as a profound reduction in visual perception. On the 6m visual acuity scale, blindness is defined as less than 3/60. On the 20ft visual acuity scale, blindness is defined as less than 20/400. On the decimal visual acuity scale, blindness is defined as less than 0.05. Blindness is typically characterized by a visual field of no greater than 10 degrees in radius around central fixation.
Abnormally large globe
MedGen UID:
344595
Concept ID:
C1855852
Finding
Diffusely large eye (with megalocornea) without glaucoma.

Recent clinical studies

Diagnosis

Goergen SK, Alibrahim E, Christie J, Dobrotwir A, Fahey M, Fender L, Frawley K, Manikkam SA, Pinner JR, Sinnott S, Romaniello R, Sandaradura SA, Taylor J, Vasudevan A, Righini A
AJNR Am J Neuroradiol 2021 Aug;42(8):1528-1534. Epub 2021 May 6 doi: 10.3174/ajnr.A7131. PMID: 33958329Free PMC Article
Kariminejad A, Radmanesh F, Rezayi AR, Tonekaboni SH, Gleeson JG
J Child Neurol 2013 May;28(5):651-7. Epub 2012 Aug 1 doi: 10.1177/0883073812448530. PMID: 22859694
Gripp KW, Hopkins E, Vinkler C, Lev D, Malinger G, Lerman-Sagie T, Dobyns WB
Am J Med Genet A 2009 May;149A(5):868-76. doi: 10.1002/ajmg.a.32732. PMID: 19353582

Therapy

Nellist M, Schot R, Hoogeveen-Westerveld M, Neuteboom RF, van der Louw EJ, Lequin MH, Bindels-de Heus K, Sibbles BJ, de Coo R, Brooks A, Mancini GM
Mol Genet Metab 2015 Mar;114(3):467-73. Epub 2014 Dec 5 doi: 10.1016/j.ymgme.2014.11.018. PMID: 25523067

Prognosis

Goergen SK, Alibrahim E, Christie J, Dobrotwir A, Fahey M, Fender L, Frawley K, Manikkam SA, Pinner JR, Sinnott S, Romaniello R, Sandaradura SA, Taylor J, Vasudevan A, Righini A
AJNR Am J Neuroradiol 2021 Aug;42(8):1528-1534. Epub 2021 May 6 doi: 10.3174/ajnr.A7131. PMID: 33958329Free PMC Article

Clinical prediction guides

Goergen SK, Alibrahim E, Christie J, Dobrotwir A, Fahey M, Fender L, Frawley K, Manikkam SA, Pinner JR, Sinnott S, Romaniello R, Sandaradura SA, Taylor J, Vasudevan A, Righini A
AJNR Am J Neuroradiol 2021 Aug;42(8):1528-1534. Epub 2021 May 6 doi: 10.3174/ajnr.A7131. PMID: 33958329Free PMC Article
Mirzaa G, Parry DA, Fry AE, Giamanco KA, Schwartzentruber J, Vanstone M, Logan CV, Roberts N, Johnson CA, Singh S, Kholmanskikh SS, Adams C, Hodge RD, Hevner RF, Bonthron DT, Braun KPJ, Faivre L, Rivière JB, St-Onge J, Gripp KW, Mancini GM, Pang K, Sweeney E, van Esch H, Verbeek N, Wieczorek D, Steinraths M, Majewski J; FORGE Canada Consortium, Boycot KM, Pilz DT, Ross ME, Dobyns WB, Sheridan EG
Nat Genet 2014 May;46(5):510-515. Epub 2014 Apr 6 doi: 10.1038/ng.2948. PMID: 24705253Free PMC Article
Rivière JB, Mirzaa GM, O'Roak BJ, Beddaoui M, Alcantara D, Conway RL, St-Onge J, Schwartzentruber JA, Gripp KW, Nikkel SM, Worthylake T, Sullivan CT, Ward TR, Butler HE, Kramer NA, Albrecht B, Armour CM, Armstrong L, Caluseriu O, Cytrynbaum C, Drolet BA, Innes AM, Lauzon JL, Lin AE, Mancini GM, Meschino WS, Reggin JD, Saggar AK, Lerman-Sagie T, Uyanik G, Weksberg R, Zirn B, Beaulieu CL; Finding of Rare Disease Genes (FORGE) Canada Consortium, Majewski J, Bulman DE, O'Driscoll M, Shendure J, Graham JM Jr, Boycott KM, Dobyns WB
Nat Genet 2012 Jun 24;44(8):934-40. doi: 10.1038/ng.2331. PMID: 22729224Free PMC Article

Supplemental Content

Recent activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...