Exome sequencing identifies de novo pathogenic variants in FBN1 and TRPS1 in a patient with a complex connective tissue phenotype

Diane B Zastrow; Patricia A Zornio; Annika Dries; Jennefer Kohler; Liliana Fernandez; Daryl Waggott; Magdalena Walkiewicz; Christine M Eng; Melanie A Manning; Ellyn Farrelly; Undiagnosed Diseases Network; Paul G Fisher; Euan A Ashley; Jonathan A Bernstein; Matthew T Wheeler

doi:10.1101/mcs.a001388

Exome sequencing identifies de novo pathogenic variants in FBN1 and TRPS1 in a patient with a complex connective tissue phenotype

Cold Spring Harb Mol Case Stud. 2017 Jan;3(1):a001388. doi: 10.1101/mcs.a001388.

Authors

Diane B Zastrow^{1

2}, Patricia A Zornio^{1

2}, Annika Dries^{1

2}, Jennefer Kohler^{1

2}, Liliana Fernandez^{1

2}, Daryl Waggott^{1

2}, Magdalena Walkiewicz³, Christine M Eng³, Melanie A Manning^{4

5}, Ellyn Farrelly⁶; Undiagnosed Diseases Network; Paul G Fisher^{1

5

7}, Euan A Ashley^{1

2

8}, Jonathan A Bernstein^{1

5

6}, Matthew T Wheeler^{1

2}

Affiliations

¹ Stanford Center for Undiagnosed Diseases, Stanford University, Stanford, California 94305, USA.
² Division of Cardiovascular Medicine, Stanford University, Stanford, California 94305, USA.
³ Baylor Miraca Genetics Laboratories, Houston, Texas 77021-2024, USA.
⁴ Department of Pathology, Stanford School of Medicine, Stanford, California 94305, USA.
⁵ Department of Pediatrics, Stanford School of Medicine, Stanford, California 94305, USA.
⁶ Lucille Packard Children's Hospital Stanford, Palo Alto, California 94304, USA.
⁷ Department of Neurology, Stanford School of Medicine, Stanford, California 94304, USA.
⁸ Department of Genetics, Stanford School of Medicine, Stanford, California 94305, USA.

Abstract

Here we describe a patient who presented with a history of congenital diaphragmatic hernia, inguinal hernia, and recurrent umbilical hernia. She also has joint laxity, hypotonia, and dysmorphic features. A unifying diagnosis was not identified based on her clinical phenotype. As part of her evaluation through the Undiagnosed Diseases Network, trio whole-exome sequencing was performed. Pathogenic variants in FBN1 and TRPS1 were identified as causing two distinct autosomal dominant conditions, each with de novo inheritance. Fibrillin 1 (FBN1) mutations are associated with Marfan syndrome and a spectrum of similar phenotypes. TRPS1 mutations are associated with trichorhinophalangeal syndrome types I and III. Features of both conditions are evident in the patient reported here. Discrepant features of the conditions (e.g., stature) and the young age of the patient may have made a clinical diagnosis more difficult in the absence of exome-wide genetic testing.

Keywords: central hypotonia; congenital diaphragmatic hernia; fourth toe clinodactyly; hammertoe; inguinal hernia; joint laxity; long philtrum; malar flattening; pes planus; protruding ear; smooth philtrum; sparse anterior scalp hair; sparse lateral eyebrow; superior pectus carinatum; thin nail; thin upper lip vermilion; thoracic scoliosis; umbilical hernia.

Abstract

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