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Interdisciplinary CompetenceMolecular Diagnostics
Know how in the analysis of genetic material.
For the benefit of patients.

IllnessIntellectual deficit + megalencephaly, differential diagnosis


Short information

Comprehensive differential diagnostic panel for Intellectual deficit + megalencephaly comprising altogether 14 curated genes according to the clinical signs

Number of genes
9 Accredited laboratory test
Examined sequence length
13,0 kb (Core-/Core-canditate-Genes)
- (Extended panel: incl. additional genes)
Analysis Duration
on request
  • EDTA-anticoagulated blood (3-5 ml)
Diagnostic indications



Gene panel

Selected genes

NameExon Length (bp)OMIM-GReferenz-Seq.Heredity
HEPACAM1251NM_152722.5AD, AR

Informations about the disease

Clinical Comment

Megalencephaly defines an increased growth of cerebral structures related to dysfunctional anomalies during the various steps of brain development in the neuronal proliferation and/or migration phases. The condition has to be distinguished from macrocephaly that presents with different clinical situations. The disorders associated with megalencephaly are classically defined into 3 groups: idiopathic or benign, metabolic, anatomic. Abnormalities of brain growth can be clinically isolated or occur as part of complex syndromes associated with other neurodevelopmental like intellectual disability. Intellectual disability is a lifelong, debilitating condition.


  • Alias: Intellectual disability + megalencephaly
  • Alias: Psycho-motor retardation + megalencephaly
  • Allelic: Breast cancer, somatic (PIK3CA)
  • Allelic: Colorectal cancer, somatic (PIK3CA)
  • Allelic: Focal cortical dysplasia, type II, somatic (MTOR)
  • Allelic: Gastric cancer, somatic (PIK3CA)
  • Allelic: Hepatocellular carcinoma, somatic (PIK3CA)
  • Allelic: Keratosis, seborrheic, somatic (PIK3CA)
  • Allelic: Macrodactyly, somatic (PIK3CA)
  • Allelic: Nevus, epidermal, somatic (PIK3CA)
  • Allelic: Nonsmall cell lung cancer, somatic (PIK3CA)
  • Allelic: Ovarian cancer, somatic (PIK3CA)
  • Alexander disease (GFAP)
  • CLAPO syndrome, somatic (PIK3CA)
  • CLOVE syndrome, somatic (PIK3CA)
  • Cowden syndrome 5 (PIK3CA)
  • Intellectual developmental disorder, AD 35 (PPP2R5D)
  • Intellectual developmental disorder, AD 36 (PPP2R1A)
  • Intellectual developmental disorder, AR 34, + variant lissencephaly (CRADD)
  • Leukoencephalopathy, cystic, without megalencephaly (RNASET2)
  • Macrocephaly/megalencephaly syndrome, AR (TBC1D7)
  • Megalencephalic leukoencephalopathy, subcortical cysts (MLC1)
  • Megalencephalic leukoencephalopathy, subcortical cysts 2A (HEPACAM)
  • Megalencephalic leukoencephalopathy, subcortical cysts 2B, remitting, with/-out ment. ret. (HEPACAM)
  • Megalencephaly-capillary malformation-polymicrogyria syndrome, somatic (PIK3CA)
  • Megalencephaly-polymicrogyria-polydactyly-hydrocephalus syndrome 2 (AKT3)
  • Megalencephaly-polymicrogyria-polydactyly-hydrocephalus syndrome 3 (CCND2)
  • Polyhydramnios, megalencephaly + symptomatic epilepsy (STRADA)
  • Smith-Kingsmore syndrome (MTOR)
Heredity, heredity patterns etc.
  • AD
  • AR
  • Multiple OMIM-Ps
ICD10 Code

Bioinformatics and clinical interpretation

No text defined