Marfan's syndrome and surgical repair of ascending aortic aneurysms

Family-based whole-exome sequencing identifies novel loss-of-function mutations of FBN1 for Marfan syndrome

Background

Marfan syndrome (MFS) is an inherited connective tissue disorder affecting the ocular, skeletal and cardiovascular systems. Previous studies of MFS have demonstrated the association between genetic defects and clinical manifestations. Our purpose was to investigate the role of novel genetic variants in determining MFS clinical phenotypes.

Methods

We sequenced the whole exome of 19 individuals derived from three Han Chinese families. The sequencing data were analyzed by a standard pipeline. Variants were further filtered against the public database and an in-house database. Then, we performed pedigree analysis under different inheritance patterns according to American College of Medical Genetics guidelines. Results were confirmed by Sanger sequencing.

Results

Two novel loss-of-function indels (c.5027_5028insTGTCCTCC, p.D1677Vfs*8; c.5856delG, p.S1953Lfs*27) and one nonsense variant (c.8034C>A, p.Y2678*) of FBN1 were identified in Family 1, Family 2 and Family 3, respectively. All affected members carried pathogenic mutations, whereas other unaffected family members or control individuals did not. These different kinds of loss of function (LOF) variants of FBN1 were located in the cbEGF region and a conserved domain across species and were not reported previously.

Conclusions

Our study extended and strengthened the vital role of FBN1 LOF mutations in the pathogenesis of MFS with an autosomal dominant inheritance pattern. We confirm that genetic testing by next-generation sequencing of blood DNA can be fundamental in helping clinicians conduct mutation-based pre- and postnatal screening, genetic diagnosis and clinical management for MFS.

Early recognition of Marfan's syndrome

PURPOSE

To describe the classical features of Marfan's syndrome to help nurse practitioners (NPs) diagnose it in the early stages of progression and perhaps prevent many of its deleterious effects.

DATA SOURCES

Selected research-based articles in the scientific literature and classic medical texts.

CONCLUSIONS

The cause of Marfan's syndrome is unknown, but studies have linked it with a disorder of chromosome 15. It is a degenerative connective tissue disorder that affects the musculoskeletal, ocular, integumentary, respiratory, and neurologic systems. The most lethal effect is on the cardiovascular system causing dissecting aortic aneurysms.

IMPLICATIONS FOR PRACTICE

Early diagnosis is essential for a positive course of management. Marfan's syndrome can have fatal consequences and is often underdiagnosed and misdiagnosed.