U.S. flag

An official website of the United States government

Format

Send to:

Choose Destination

Megalencephaly-polydactyly syndrome(MPAPA)

MedGen UID:
1855924
Concept ID:
C5935591
Disease or Syndrome
Synonym: MPAPA
 
Gene (location): MYCN (2p24.3)
 
Monarch Initiative: MONDO:0958279
OMIM®: 620748

Definition

Megalencephaly-polydactyly syndrome (MPAPA) is an autosomal dominant disorder characterized by megalencephaly, ventriculomegaly, postaxial polydactyly, and, notably, neuroblastoma during infancy (summary by Nishio et al., 2023). [from OMIM]

Clinical features

From HPO
Neuroblastoma
MedGen UID:
18012
Concept ID:
C0027819
Neoplastic Process
ALK-related neuroblastic tumor susceptibility is characterized by increased risk for neuroblastic tumors including neuroblastomas, ganglioneuroblastomas, and ganglioneuromas. Neuroblastomas are a more malignant tumor and ganglioneuromas a more benign tumor. Depending on the histologic findings, ganglioneuroblastomas can behave in a more aggressive fashion, like neuroblastomas, or in a benign fashion, like ganglioneuromas. The overall penetrance of a germline ALK pathogenic variant is approximately 50%, with the risk for neuroblastic tumor development highest in infancy and decreasing by late childhood.
Hydronephrosis
MedGen UID:
42531
Concept ID:
C0020295
Disease or Syndrome
Severe distention of the kidney with dilation of the renal pelvis and calices.
Postaxial polydactyly
MedGen UID:
67394
Concept ID:
C0220697
Congenital Abnormality
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 CIBAR1 gene (617273) on chromosome 8q22; and PAPA10 (618498), caused by mutation in the KIAA0825 gene (617266) on chromosome 5q15.
Toe syndactyly
MedGen UID:
75581
Concept ID:
C0265660
Congenital Abnormality
Webbing or fusion of the toes, involving soft parts only or including bone structure. Bony fusions are referred to as "bony" Syndactyly if the fusion occurs in a radio-ulnar axis. Fusions of bones of the toes in a proximo-distal axis are referred to as "Symphalangism".
Short middle phalanx of finger
MedGen UID:
337690
Concept ID:
C1846950
Finding
Short (hypoplastic) middle phalanx of finger, affecting one or more fingers.
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.
Postnatal growth retardation
MedGen UID:
395343
Concept ID:
C1859778
Finding
Slow or limited growth after birth.
Meckel diverticulum
MedGen UID:
9917
Concept ID:
C0025037
Congenital Abnormality
Meckel's diverticulum is a congenital diverticulum located in the distal ileum.
Gastrointestinal atresia
MedGen UID:
871218
Concept ID:
C4025697
Disease or Syndrome
Low-set ears
MedGen UID:
65980
Concept ID:
C0239234
Congenital Abnormality
Upper insertion of the ear to the scalp below an imaginary horizontal line drawn between the inner canthi of the eye and extending posteriorly to the ear.
Posteriorly rotated ears
MedGen UID:
96566
Concept ID:
C0431478
Congenital Abnormality
A type of abnormal location of the ears in which the position of the ears is characterized by posterior rotation (the superior part of the ears is rotated towards the back of the head, and the inferior part of the ears towards the front).
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.
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).
Generalized-onset seizure
MedGen UID:
115963
Concept ID:
C0234533
Disease or Syndrome
A generalized-onset seizure is a type of seizure originating at some point within, and rapidly engaging, bilaterally distributed networks. The networks may include cortical and subcortical structures but not necessarily the entire cortex.
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.
Congenital bilateral perisylvian syndrome
MedGen UID:
337000
Concept ID:
C1845668
Disease or Syndrome
Polymicrogyria (PMG) is a malformation of cortical development in which the brain surface is irregular and the normal gyral pattern replaced by multiple small, partly fused gyri separated by shallow sulci. Microscopic examination shows a simplified 4-layered or unlayered cortex. Several patterns of PMG, including bilateral frontal, bilateral perisylvian, and bilateral mesial occipital PMG, have been described on the basis of their topographic distribution. All but the perisylvian form appear to be rare. Bilateral perisylvian PMG (BPP) often results in a typical clinical syndrome that is manifested by mild mental retardation, epilepsy, and pseudobulbar palsy, which causes difficulties with expressive speech and feeding (Kuzniecky et al., 1993). PMG may be a feature of other conditions as well (see, e.g., 300643).
Motor delay
MedGen UID:
381392
Concept ID:
C1854301
Finding
A type of Developmental delay characterized by a delay in acquiring motor skills.
Ventriculomegaly
MedGen UID:
480553
Concept ID:
C3278923
Finding
An increase in size of the ventricular system of the brain.
Intellectual disability
MedGen UID:
811461
Concept ID:
C3714756
Mental or Behavioral Dysfunction
Intellectual disability, previously referred to as mental retardation, is characterized by subnormal intellectual functioning that occurs during the developmental period. It is defined by an IQ score below 70.
Diaphragmatic eventration
MedGen UID:
8359
Concept ID:
C0011981
Congenital Abnormality
A congenital failure of muscular development of part or all of one or both hemidiaphragms, resulting in superior displacement of abdominal viscera and altered lung development.
Retrognathia
MedGen UID:
19766
Concept ID:
C0035353
Congenital Abnormality
An abnormality in which the mandible is mislocalised posteriorly.
Respiratory distress
MedGen UID:
96907
Concept ID:
C0476273
Sign or Symptom
Respiratory distress is objectively observable as the physical or emotional consequences from the experience of dyspnea. The physical presentation of respiratory distress is generally referred to as labored breathing, while the sensation of respiratory distress is called shortness of breath or dyspnea.
Tracheomalacia
MedGen UID:
215296
Concept ID:
C0948187
Disease or Syndrome
Congenital tracheomalacia is a rare condition where the trachea is soft and flexible causing the tracheal wall to collapse when exhaling, coughing or crying, that usually presents in infancy, and that is characterized by stridor and noisy breathing or upper respiratory infections. Tracheomalacia improves by the age of 18-24 months.
High palate
MedGen UID:
66814
Concept ID:
C0240635
Congenital Abnormality
Height of the palate more than 2 SD above the mean (objective) or palatal height at the level of the first permanent molar more than twice the height of the teeth (subjective).
Abnormal facial shape
MedGen UID:
98409
Concept ID:
C0424503
Finding
An abnormal morphology (form) of the face or its components.
Epicanthus
MedGen UID:
151862
Concept ID:
C0678230
Congenital Abnormality
Epicanthus is a condition in which a fold of skin stretches from the upper to the lower eyelid, partially covering the inner canthus. Usher (1935) noted that epicanthus is a normal finding in the fetus of all races. Epicanthus also occurs in association with hereditary ptosis (110100).
Square face
MedGen UID:
371253
Concept ID:
C1832127
Finding
Facial contours, as viewed from the front, show a broad upper face/cranium and lower face/mandible, creating a square appearance.
Depressed nasal bridge
MedGen UID:
373112
Concept ID:
C1836542
Finding
Posterior positioning of the nasal root in relation to the overall facial profile for age.
Prominent forehead
MedGen UID:
373291
Concept ID:
C1837260
Finding
Forward prominence of the entire forehead, due to protrusion of the frontal bone.
Anteverted nares
MedGen UID:
326648
Concept ID:
C1840077
Finding
Anteriorly-facing nostrils viewed with the head in the Frankfurt horizontal and the eyes of the observer level with the eyes of the subject. This gives the appearance of an upturned nose (upturned nasal tip).
Wide nasal bridge
MedGen UID:
341441
Concept ID:
C1849367
Finding
Increased breadth of the nasal bridge (and with it, the nasal root).
Wide nasal base
MedGen UID:
341506
Concept ID:
C1849667
Finding
Increased distance between the attachments of the alae nasi to the face.
Thick eyebrow
MedGen UID:
377914
Concept ID:
C1853487
Finding
Increased density/number and/or increased diameter of eyebrow hairs.
Short nose
MedGen UID:
343052
Concept ID:
C1854114
Finding
Distance from nasion to subnasale more than two standard deviations below the mean, or alternatively, an apparently decreased length from the nasal root to the nasal tip.
Long philtrum
MedGen UID:
351278
Concept ID:
C1865014
Finding
Distance between nasal base and midline upper lip vermilion border more than 2 SD above the mean. Alternatively, an apparently increased distance between nasal base and midline upper lip vermilion border.
Laterally extended eyebrow
MedGen UID:
869034
Concept ID:
C4023451
Finding
An eyebrow that extends laterally beyond the orbital rim rather than turning gently downward at that location.
Hypertelorism
MedGen UID:
9373
Concept ID:
C0020534
Finding
Although hypertelorism means an excessive distance between any paired organs (e.g., the nipples), the use of the word has come to be confined to ocular hypertelorism. Hypertelorism occurs as an isolated feature and is also a feature of many syndromes, e.g., Opitz G syndrome (see 300000), Greig cephalopolysyndactyly (175700), and Noonan syndrome (163950) (summary by Cohen et al., 1995).

Supplemental Content

Recent activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...