MLIS2
Microlissencephaly Type B or Barth microlissencephaly syndrome: is a microlissencephaly with thick cortex, severe cerebellar and brainstem hypoplasia. The Barth-type of MLIS is the most severe of all the known lissencephaly syndromes.This phenotype consists of polyhydramnios (probably due to poor fetal swallowing), severe congenital microcephaly, weak respiratory effort, and survival for only a few hours or days. Barth described two siblings with this type as having a very low brainweight, wide ventricles, a very thin neopallium, absent corpus callosum and absent olfactory nerve. MLIS3
Microlissencephaly with intermediate cortex and abrupt anteroposterior gradient

MLIS4
Microlissencephaly with mildly to moderately thick (6–8 mm) cortex, callosal agenesis

Presentation
Microlissencephalic patients suffer from spasticity, seizures, severe developmental delay and intellectual disabilities with survival varying from days to years. Patients may also have dysmorphic craniofacial features, abnormal genitalia, and arthrogryposis.Microlissencephaly may arise as a part of Baraitser-Winter syndrome which comprises also ptosis, coloboma, hearing loss and learning disability. Moreover, it is the distinct developmental brain abnormality in "microcephalic osteodysplastic primordial dwarfism" (MOPD1). Microlissencephaly may be accompanied by micromelia as in Basel-Vanagaite-Sirota syndrome (a.k.a. Microlissencephaly-Micromelia syndrome). Pathophysiology
The genetic basis and pathophysiology of microlissencephaly are still not completely understood. Most cases of microlissencephaly are described in consanguineous families suggesting an autosomal recessive inheritance. Mutation of RELN gene or CIT could cause MLIS. Human NDE1 mutations and mouse Nde1 loss lead to cortical lamination deficits, which, together with reduced neuronal production cause microlissencephaly. Homozygous frameshift mutations in NDE1 gene was found to cause microlissencephaly with up to 90% reduction in brain mass and seizures starting early in life.
Fovilles syndrome is caused by the blockage of the perforating branches of the basilar artery in the region of the brainstem known as the pons. It is most frequently caused by vascular disease or tumors involving the dorsal pons. Structures affected by the infarct are the dorsal pons(pontine tegmentum) which comprises paramedian pontine reticular formation (PPRF), nuclei of cranial nerves VI and VII, corticospinal tract, medial lemniscus, and the medial longitudinal fasciculus. There is involvement of the fifth to eighth cranial nerves, central sympathetic fibres (Horner syndrome) and horizontal gaze palsy. Presentation
This produces ipsilateral horizontal gaze palsy and facial nerve palsy and contralateral hemiparesis, hemisensory loss, and internuclear ophthalmoplegia. Diagnosis
Treatment
History
Fovilles syndrome was initially described by Achille-Louis Foville, a French physician, in 1859. References


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