FKTN Compound Heterozygosity Associated With Walker-Warburg Spectrum Features and Severe Cochlear Hypoplasia With Preserved Basal Turn.
Yuki Koyano, Rena Miura-Fuchino, Tatsuo Kono et al.
✦ AI-curated · Sources linked
Case in brief
A female neonate presented with marked hypotonia and early respiratory compromise. Trio sequencing identified compound heterozygous FKTN variants: a 3-kb founder insertion and an early nonsense variant. Brain MRI showed extensive cobblestone lissencephaly, while temporal bone imaging demonstrated bilateral severe cochlear hypoplasia with a preserved basal turn; sensorineural hearing loss was also present. Hydrocephalus and a clear Z-shaped brainstem configuration were absent. The findings were considered consistent with Walker-Warburg spectrum dystroglycanopathy associated with severe FKTN deficiency.
What made this case unusual
Severe bilateral cochlear hypoplasia with preservation of the basal turn accompanied Walker-Warburg spectrum brain findings, despite the absence of hydrocephalus or a clear Z-shaped brainstem configuration.
Diagnostic / clinical pearl
In severe FKTN-related dystroglycanopathy, assess the inner ear as well as the brain: cochlear malformation and sensorineural hearing loss may accompany cobblestone lissencephaly.
Why it matters
The case adds inner ear malformation to the described phenotypic spectrum of severe FKTN deficiency.