Microlissencephaly

Microlissencephaly
Microlissencephaly in a 27 WG (week of gestation) foetus with TUBB2B mutation. Macroscopical view of the left hemisphere showing agyria, absent sylvian fissure and absent olfactory bulb.
SpecialtyNeurology
TypesNorman-Roberts syndrome, Barth syndrome, MLIS3, MLIS4
CausesGenetic or viral

Microlissencephaly (MLIS) is a rare congenital brain disorder that combines severe microcephaly (small head) with lissencephaly (smooth brain surface due to absent sulci and gyri). Microlissencephaly is a heterogeneous disorder, i.e. it has many different causes and a variable clinical course.[1] Microlissencephaly is a malformation of cortical development (MCD) that occurs due to failure of neuronal migration between the third and fifth month of gestation as well as stem cell population abnormalities.[2][3] Numerous genes have been found to be associated with microlissencephaly, however, the pathophysiology is still not completely understood.

The combination of lissencephaly with severe congenital microcephaly is designated as microlissencephaly only when the cortex is abnormally thick. If such combination exists with a normal cortical thickness (2.5 to 3 mm[4]), it is known as "microcephaly with simplified gyral pattern" (MSGP).[5] Both MLIS and MSGP have a much more severe clinical course than microcephaly alone.[6] They are inherited in autosomal recessive manner.[7] Prior to 2000, the term "microlissencephaly" was used to designate both MLIS and MSGP.[8]

  1. ^ Barkovich, A.; Ferriero, Donna; Barr, R.; Gressens, P.; Dobyns, W.; Truwit, Ch.; Evrard, Ph. (1998). "Microlissencephaly: A Heterogeneous Malformation of Cortical Development". Neuropediatrics. 29 (3): 113–119. doi:10.1055/s-2007-973545. ISSN 0174-304X. PMID 9706619. S2CID 21068913.
  2. ^ Cite error: The named reference Razek was invoked but never defined (see the help page).
  3. ^ Cicuto Ferreira Rocha, Nelci Adriana; de Campos, Ana Carolina; Cicuto Ferreira Rocha, Fellipe; Pereira dos Santos Silva, Fernanda (2017-11-01). "Microcephaly and Zika virus: Neuroradiological aspects, clinical findings and a proposed framework for early evaluation of child development". Infant Behavior and Development. 49 (Supplement C): 70–82. doi:10.1016/j.infbeh.2017.07.002. PMID 28755567.
  4. ^ Hutton, Chloe; De Vita, Enrico; Ashburner, John; Deichmann, Ralf; Turner, Robert (2008-05-01). "Voxel-based cortical thickness measurements in MRI". NeuroImage. 40 (4): 1701–1710. doi:10.1016/j.neuroimage.2008.01.027. ISSN 1053-8119. PMC 2330066. PMID 18325790.
  5. ^ Swaiman, Kenneth F.; Ashwal, Stephen; Ferriero, Donna M.; Schor, Nina F. (2011-11-11). Swaiman's Pediatric Neurology - E-Book: Principles and Practice. Elsevier Health Sciences. ISBN 978-0323089111.
  6. ^ Gaitanis, John N.; Walsh, Christopher A. (May 2004). "Genetics of disorders of cortical development". Neuroimaging Clinics of North America. 14 (2): 219–229, viii. doi:10.1016/j.nic.2004.03.007. ISSN 1052-5149. PMID 15182816.
  7. ^ Martin, Richard J.; Fanaroff, Avroy A.; Walsh, Michele C. (2014-08-20). Fanaroff and Martin's Neonatal-Perinatal Medicine E-Book: Diseases of the Fetus and Infant. Elsevier Health Sciences. ISBN 9780323295376.
  8. ^ Verloes, Alain; Drunat, Séverine; Gressens, Pierre; Passemard, Sandrine (1993). "Primary Autosomal Recessive Microcephalies and Seckel Syndrome Spectrum Disorders". In Adam, Margaret P.; Ardinger, Holly H.; Pagon, Roberta A.; Wallace, Stephanie E.; Bean, Lora J.H.; Mefford, Heather C.; Stephens, Karen; Amemiya, Anne; Ledbetter, Nikki (eds.). GeneReviews. Seattle, Washington: University of Washington, Seattle. PMID 20301772.