Lateral meningocele syndrome (LMS), also known as Lehman syndrome, is a very rare skeletal disorder with facial anomalies, hypotonia and meningocele-related neurologic dysfunction. Facial features of LMS include hypertelorism and telecanthus, high arched eyebrows, ptosis, midfacial hypoplasia, micrognathia, high and narrow palate, low-set ears and a hypotonic appearance. Patients may also have hyperextensibility, hernias, scoliosis and aortic dilation, a high-pitched nasal voice, wormian bones and osteolysis.
LMS is caused by truncating variants in the last coding exon of the NOTCH3 gene, resulting in premature termination of the protein and truncation of the negative regulatory proline-glutamate-serine-threonine rich intracellular product (Gripp KW et al 2015 Am J Med Genet Part A 167A:271–281).
There is phenotypic overlap of LMS with Hajdu-Cheney syndrome (HCS), caused by truncating variants in the last coding exon of NOTCH2.
The laboratory participates in the European Molecular Genetics Quality Network (EMQN) sequencing scheme.