STICKLER SYNDROME

Corrine Fillman, M.S., C.G.C.

Connective Tissue Gene Tests (CTGT)

6580 Snowdrift Road, Suite 300

Allentown, PA 18106

OUTLINE• Stickler Syndrome

– Clinical Findings

– Genes

– Connective Tissue & Collagen

– Autosomal Dominant Stickler syndrome• Marshall syndrome

– Autosomal Recessive Stickler syndrome

• How is Stickler & Marshall Syndrome Diagnosed?– Clinical Diagnosis

– Molecular Diagnosis-CTGT

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STICKLER SYNDROME AFFECTS MANY PARTS OF THE BODY:

Eyes: Nearsightedness

Cataracts Retinal detachment

Ears: Hearing Loss

Bones: Chondrodysplasia

Joints: Early-onset arthritis

Oral/Facial: Cleft palateBifid uvulaSmall chin

Pierre-Robin sequenceFlat cheeks

Flat nasal bridge

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STICKLER SYNDROMEA GENETIC DISORDER

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COL2A1

COL11A1

COL11A2

COL9A1

COL9A2

COL9A3

STICKLER SYNDROME GENES

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– The genes associated with Stickler syndrome are responsible for making proteins called collagens. Specifically collagen type II, XI & IX.

– There are many types of collagens and collagens are found throughout the body in our connective tissue.

– Connective tissue is a material that provides strength and support for organs and tissues.

– The collagen types associated with Stickler syndrome are found primarily in cartilage, part of the clear gel that fills the eyeball (the vitreous) and the inner ear.

STICKLER SYNDROMEA CONNECTIVE TISSUE DISORDER

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STICKLER SYNDROMECOLLAGEN PROTEIN

The collagen protein is made of 3 protein chains wrapped around one another like a rope.

Collagen II protein is made of 3 identical protein chains made from the COL2A1 gene.

Collagen XI protein is made of 3 different protein chains.1 chain is made from the COL11A1 gene1 chain is made from the COL11A2 gene1 chain is made from the COL11A3 gene

Collagen IX protein is made of 3 different protein chains.1 chain is made from the COL9A1 gene1 chain is made from the COL9A2 gene1 chain is made from the COL9A3 gene 7

• The majority of individuals with Stickler syndrome have autosomal dominant Stickler syndrome.

• The genes associated with autosomal dominant Stickler syndrome are COL2A1, COL11A1 and COL11A2.

• First-degree relatives (children, siblings and parents) have a 50% chance of also having Stickler

syndrome.

STICKLER SYNDROMEAUTOSOMAL DOMINANT

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Stickler syndrome, type I•80-90% of individuals with Stickler syndrome have mutations in the COL2A1 gene.•Autosomal dominant inheritance.•Individuals may have a “membranous” type 1 vitreous anomaly.•Mutations in the COL2A1 gene cause Stickler syndrome, type I.•Individuals with mutations in exon 2 of the COL2A1 gene have an ocular variant of Stickler syndrome.

– Individuals may present with typical eye findings including an empty vitreous and/or early-onset retinal detachment but there are minimal or absent findings in the ears, bones, joints and oral/facial structures.

There are differences in an individual’s clinical findings depending upon the affected gene and mutation

STICKLER SYNDROMETYPES

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THERE ARE DIFFERENCES IN AN

INDIVIDUAL’S CLINICAL FINDINGS

DEPENDING UPON THE AFFECTED GENE AND MUTATION

COL2A1 mutations are associated with more than one disorders including:

Stickler syndrome, type I Stickler syndrome, type I, nonsyndromic ocular

Other Conditions:Achondrogenesis, type II / Hypochondrogenesis Spondyloepiphyseal dysplasia congenita Spondyloepimetaphyseal dysplasia, Strudwick typeKniest dysplasiaSpondyloepiphyseal dysplasia late onset Avascular necrosis of femoral head Early-onset osteoarthritis

In the case of COL2A1, the type of mutation and the location within the gene will result in different clinical findings:

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Stickler syndrome, type II• Mutations in the COL11A1 gene cause Stickler

syndrome, type II.• 10-20% of individuals with Stickler syndrome

have mutations in the COL11A1 gene.• Autosomal dominant inheritance. • Individuals may have a “beaded” type 2 vitreous

anomaly.

There are differences in an individual’s clinical findings depending upon the affected gene and mutation

STICKLER SYNDROMETYPES

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COL11A1 mutations are associated with more than one disorder including:

Stickler syndrome, type II

Other Conditions:Marshall syndromeFibrochondrogenesis

THERE ARE DIFFERENCES IN AN INDIVIDUAL’S CLINICAL FINDINGS

DEPENDING UPON THE AFFECTED GENE AND MUTATION

In the case of COL11A1, the type of mutation and the location within the gene will result in different clinical findings:

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MARSHALL SYNDROME

• Shares many features in common with Stickler syndrome including: nearsightedness, retinal detachment, hearing loss, cleft palate and Pierre-Robin sequence.

• In addition, patients may have early-onset hearing loss, short stature, abnormalities in cranial ossification, and more pronounced facial features including markedly flat cheeks with a flat nasal bridge and a short upturned nose.

• Mutations in the COL11A1 gene cause Marshall syndrome.

• Mutations in this gene also cause Stickler syndrome, type II.

• Autosomal dominant inheritance and first-degree relatives (children, siblings & parents) have a 50% chance of also having Marshall syndrome.

Annunen et al., 1999. Am J Hum Genet 65:974-983.

14A -B-Stickler syndromeC-F- Marshall syndrome

Stickler syndrome, type III• Mutations in the COL11A2 gene cause a non-

ocular form of Stickler syndrome.• Autosomal dominant inheritance.• Individuals have cleft palate and/or Pierre-Robin

sequence, hearing loss and early-onset osteoarthritis.

• Individuals do not have eye findings typically associated with Stickler syndrome.

There are differences in an individual’s clinical findings depending upon the affected gene and mutation

STICKLER SYNDROMETYPES

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COL11A2 mutations are associated with more than one disorder including:

Stickler syndrome, type III

Other Conditions:Otospondylomegaepiphyseal dysplasia Weissenbacher-Zweymuller syndrome

THERE ARE DIFFERENCES IN AN INDIVIDUAL’S CLINICAL FINDINGS

DEPENDING UPON THE AFFECTED GENE AND MUTATION

In the case of COL11A2, the type of mutation and the location within the gene will result in different clinical findings:

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• It is not known how many individuals with Stickler syndrome have autosomal recessive inheritance.

• Mutations in the COL9A1, COL9A2 and COL9A3 genes cause Stickler syndrome, autosomal recessive.

• Siblings of an affected individual have a 25% chance of also having Stickler syndrome and a 50% chance of being an unaffected carrier.

• Individuals present with clinical symptoms similar to Stickler syndrome type I/II.

STICKLER SYNDROMEAUTOSOMAL RECESSIVE

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STICKLER SYNDROMEAUTOSOMAL RECESSIVE

•2006-COL9A1Van Camp et al., 2006. Am J Hum Genet 79:449-457.

•Severe myopia, vitreoretinal degeneration,hearing loss, chondrodysplasia •2010- COL9A2 & COL9A3-Canine studiesGoldstein et al., 2010. Mamm Genome 21:398-408.

•Oculoskeletal dysplasia similar to STL1 & STL2 segregates as an autosomal recessive trait in Labrador Retriever and Samoyed dog breeds•Vitreous dysplasia, retinal detachment, cataracts, short-limb dwarfism

•2011- COL9A2Baker et al., 2011. Am J Med Genet Part A 9999: 1-5.

•Severe myopia,vitreoretinal degeneration, retinal detachment, hearing loss

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STICKLER SYNDROMEAUTOSOMAL RECESSIVE

Baker et al., 2011. Am J Med Genet Part A 9999: 1-5

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HOW IS STICKLER SYNDROME AND MARSHALL SYNDROME DIAGNOSED?

• Clinical Diagnosis: made by evaluating a patient’s medical and family history and having a thorough physical exam by a physician and/or specialists. – A physician can use published literature and references that

describe the clinical findings to help make a diagnosis. – There is a wide range of clinical findings, and individuals in the

same family may have different findings and varying degrees of severity.

• Molecular Diagnosis (genetic testing): made by identifying a mutation in one of the associated genes. – Molecular testing is available in CLIA approved laboratories

and requires a blood sample from the individual suspected to have a diagnosis.

– Can confirm a suspected clinical diagnosis.– Results from a molecular diagnosis can be used for

surveillance and management. – Results can be used to confirm or rule out the diagnosis in at

risk family members.21

CONNECTIVE TISSUE GENE TESTS

Director of Research, Development and TechnologyLeena Ala-Kokko, M.D., Ph.D.

CEO and Medical DirectorJames Hyland, M.D., Ph.D.

•CTGT was established in June, 2004 and is located in Allentown, PA.•About 20 employees. •CLIA & CAP certified. •Currently test for over 100 different genetic disorders.•Offer many different technologies for testing.•CTGT in continually adding new tests and developing new technologies. •CTGT offers family testing and prenatal testing for all our genes.•CTGT has a rapid turnaround time averaging about 2 weeks.

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CONNECTIVE TISSUE GENE TESTSMOLECULAR DIAGNOSIS

2 Test Requests:1.Sequencing2.Deletion/Duplication

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Probe: COL11A1 Gene

CONNECTIVE TISSUE GENE TESTSSEQUENCING

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CONNECTIVE TISSUE GENE TESTSSEQUENCING

COL11A1 Gene

The cat ran home.The mat ran home. 25

Test request: Marshall syndrome COL11A1Clinical Findings:3 year old boyRobin Sequence (cleft palate & small chin)Flat faceBilateral conductive hearing lossSevere myopia (legally blind)

Result: COL11A1 IVS50+1G>A

Result: COL11A1 IVS50+1G>A

CONNECTIVE TISSUE GENE TESTSSEQUENCING

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CONNECTIVE TISSUE GENE TESTSDELETION/DUPLICATION

Test Sampl

e

Control Sample

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CONNECTIVE TISSUE GENE TESTSDELETION/DUPLICATION

Cleft palateFlat face

Sequencing Results:COL2A1 sequencing negativeCOL11A1 sequencing negativeCOL11A2 sequencing negative

Clinical Findings:2 year old boyFlat faceMyopia at 15 months oldShort upturned noseCleft palate

Deletion/Duplication Results:COL11A1 deletion exons 47-62

Deletion/Duplication Results:COL2A1 deletion/duplication negativeCOL11A1 deletion exons 47-62

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CONNECTIVE TISSUE GENE TESTSDELETION/DUPLICATION

COL11A1 gene no deletion

COL11A1 gene deletion of exons 47-62

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CONNECTIVE TISSUE GENE TESTS SEQUENCING VS.

DELETION/DUPLICATION

Sequencing-looks for small spelling errors in the gene’s set of instructions.

Deletion/Duplication-looks for large sections of the instructions that are missing.

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CONNECTIVE TISSUE GENE TESTSSTICKLER SYNDROME TESTING

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Gene Sequencing Deletion/Duplication COL2A1 X XCOL11A1 X XCOL11A2 X XCOL9A1 X XCOL9A2 X XCOL9A3 X X

•CTGT offers both sequencing and deletion/duplication testing for all the genes currently associated with Stickler syndrome.

•Having a genetic test is a choice not a requirement.

•Genetic testing is a personal decision and the decision is different for each family and each person within a family.

THANKYOU

Corrine Fillman, M.S., C.G.C.

Connective Tissue Gene Tests (CTGT)

6580 Snowdrift Road, Suite 300

Allentown, PA 18106