Deletions within the chromosome 14q13 region contribute to neurodevelopmental symptoms such as hypotonia and developmental delay.
The article discusses two siblings – a boy and a girl – with a unique, familial 2.4 Mb deletion within 14q13.1q14.3. Shared symptoms for both siblings include seizures, developmental delay, hypotonia (low muscle tone), visual impairment and facial dysmorphism. The boy additionally revealed failure to thrive, intellectual disability, and partial hearing impairment. While the sister appears to have milder developmental issues, she does have hemophagocytic lymphohistiocytosis (HLH; an overactive immune system that damages the body) as a unique symptom.
The deleted segment includes 22 genes which were lost in both sibs. However, no data is available relating which genes within this region may be contributing to these symptoms. Regarding the girl – whose deletion is the same as her brother’s – loss of NFKBIA may have contributed to the development of HLH. Paternal origin of the deletion was shown using haplotype analysis of chromosome 14. Karyotype of the father (in lymphocytes) was completely normal and he had no clinical abnormalities. Most likely he has a gonadal mosaicism.
These siblings share similar symptoms as another 14q13 deletion case from a different study, whose symptoms include developmental delay, hypotonia, epilepsy, and HLH. Through this comparison, one can deduce that deletion within the 14q13 region contributes to the neurodevelopmental symptoms presented in these cases. However, more cases need to be analyzed before distinct symptoms and genes of interest can be deduced.
Liu, et al. “Child Neurology: Siblings with infantile epilepsy and developmental delay”. Neurology. 2018,
- 91 (3), 143-147.
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