Truncating mutations in the last exon of NOTCH3 cause lateral meningocele syndrome

Karen W. Gripp, Katherine M. Robbins, Nara L. Sobreira, P. Dane Witmer, Lynne M. Bird, Kristiina Avela, Outi Makitie, Daniela Alves, Jacob S. Hogue, Elaine H. Zackai, Kimberly F. Doheny, Deborah L. Stabley, Katia Sol-Church

Research output: Contribution to journalArticlepeer-review

Abstract

Lateral meningocele syndrome (LMS, OMIM%130720), also known as Lehman syndrome, is a very rare skeletal disorder with facial anomalies, hypotonia and meningocele-related neurologic dysfunction. The characteristic lateral meningoceles represent the severe end of the dural ectasia spectrum and are typically most severe in the lower spine. 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. Hyperextensibility, hernias and scoliosis reflect a connective tissue abnormality, and aortic dilation, a high-pitched nasal voice, wormian bones and osteolysis may be present. Lateral meningocele syndrome has phenotypic overlap with Hajdu-Cheney syndrome. We performed exome resequencing in five unrelated individuals with LMS and identified heterozygous truncating NOTCH3 mutations. In an additional unrelated individual Sanger sequencing revealed a deleterious variant in the same exon 33. In total, five novel de novo NOTCH3 mutations were identified in six unrelated patients. One had a 26bp deletion (c.6461_6486del, p.G2154fsTer78), two carried the same single base pair insertion (c.6692_93insC, p.P2231fsTer11), and three individuals had a nonsense point mutation at c.6247A>T (pK2083*), c.6663C>G (p.Y2221*) or c.6732C>A, (p.Y2244*). All mutations cluster into the last coding exon, resulting in premature termination of the protein and truncation of the negative regulatory proline-glutamate-serine-threonine rich PEST domain. Our results suggest that mutant mRNA products escape nonsense mediated decay. The truncated NOTCH3 may cause gain-of-function through decreased clearance of the active intracellular product, resembling NOTCH2 mutations in the clinically related Hajdu-Cheney syndrome and contrasting the NOTCH3 missense mutations causing CADASIL.

Original languageEnglish (US)
Pages (from-to)271-281
Number of pages11
JournalAmerican Journal of Medical Genetics, Part A
Volume167
Issue number2
DOIs
StatePublished - Feb 1 2015

Keywords

  • Dural ectasia
  • Hajdu-Cheney syndrome
  • Lateral meningocele syndrome
  • Lehman syndrome
  • NOTCH3
  • PEST domain

ASJC Scopus subject areas

  • Genetics
  • Genetics(clinical)

Fingerprint

Dive into the research topics of 'Truncating mutations in the last exon of NOTCH3 cause lateral meningocele syndrome'. Together they form a unique fingerprint.

Cite this