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Genetic and Rare Diseases Information Center (GARD)

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Other Names for this Disease
  • Hydranencephaly and microcephaly
  • MHAC
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Microhydranencephaly (MHAC) is a severe abnormality of brain development characterized by both microcephaly and hydranencephaly. Signs and symptoms may include severe microcephaly, scalp rugae (a series of ridges), and profound developmental delay.[1] Familial occurrence of the condition is very rare but it has been reported in a few families. It has been suggested that MHAC is possibly inherited in an autosomal recessive manner.[1][2]
Last updated: 4/11/2012


  1. Behunova J, Zavadilikova E, Bozoglu TM, Gunduz A, Tolun A, Yalcinkaya C. Familial microhydranencephaly, a family that does not map to 16p13.13-p12.2: relationship with hereditary fetal brain degeneration and fetal brain disruption sequence. Clin Dysmorphol. July 2010; 19(3):107-118.
  2. Marla J. F. O'Neill. MICROHYDRANENCEPHALY; MHAC. OMIM. June 30, 2004; Accessed 4/11/2012.
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  • The Online Mendelian Inheritance in Man (OMIM) is an catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Microhydranencephaly. Click on the link to view a sample search on this topic.