mucopolysaccharides medical genetics dr derakhshandeh, phd

MucopolysacchariMucopolysaccharidesdes

Medical GeneticsMedical Genetics

Dr Derakhshandeh, PhDDr Derakhshandeh, PhD

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Definition Definition

A gel-like substance found in:A gel-like substance found in:

body cellsbody cells mucous secretionsmucous secretions synovial fluidssynovial fluids

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MucopolysaccharidoMucopolysaccharidosesses

Genetic disordersGenetic disorders

Deficiency of enzymes necessary Deficiency of enzymes necessary to breakdown to breakdown mucopolysaccharides (MPS) mucopolysaccharides (MPS)

Excessive accumulation of Excessive accumulation of mucopolysaccharides in body mucopolysaccharides in body tissues tissues

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MucopolysaccharidoMucopolysaccharidosesses

Results:Results:– many serious physical disorders many serious physical disorders – Various genetic deformities such Various genetic deformities such

as:as:

skeletal deformities (especially of skeletal deformities (especially of the face)the face)

mental retardationmental retardation

decreased life expectancydecreased life expectancy

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ExamplesExamples

Hunter syndromeHunter syndromeHurler syndromeHurler syndromeScheie syndromeScheie syndromeSanfilippo syndromeSanfilippo syndromeMorquio diseaseMorquio diseaseMaroteaux-Lamy Maroteaux-Lamy syndromesyndrome

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Hurler syndrome Hurler syndrome type Itype I

((Alpha-L-iduronate Alpha-L-iduronate deficiencydeficiency ) )

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Hurler syndrome Hurler syndrome type Itype I

DefinitionDefinition

An inherited disease (AR)An inherited disease (AR)

Storage of abnormal Storage of abnormal quantities of this material quantities of this material (mucopolysaccharide) in (mucopolysaccharide) in different body tissues is different body tissues is responsible for the responsible for the symptoms and appearance symptoms and appearance of the diseaseof the disease

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Hurler syndrome (type Hurler syndrome (type I)I)

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Hurler syndrome type IHurler syndrome type I

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Key Symptom Images

Hernia

Corneal clouding

Coarse facial features

Claw hand

Mucopolysaccharidosis I Mucopolysaccharidosis I ((MPS IMPS I) ) DiseaseDisease ))Hurler, HurlerHurler, Hurler--Scheie, Scheie SyndromesScheie, Scheie Syndromes((

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Causes of the Hurler Causes of the Hurler syndromesyndrome

Inherited as an autosomal Inherited as an autosomal recessive traitrecessive trait

Metabolic defect: Metabolic defect: inability inability – The body's to make an The body's to make an

enzyme: enzyme:

lysosomal alpha-L-iduronaselysosomal alpha-L-iduronase

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incidence & and risk incidence & and risk factorsfactors

Approximately 1 in Approximately 1 in 150,000 infants are 150,000 infants are affectedaffected

Newborn infants with this Newborn infants with this defect appear normal at defect appear normal at birth birth

By the end of the first By the end of the first year, signs of impending year, signs of impending problems begin to developproblems begin to develop

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MPS (Type I)MPS (Type I)

The children slowly developThe children slowly develop

Coarse, thick, facial Coarse, thick, facial featuresfeatures

Prominent dark eyebrowsProminent dark eyebrows

Progressive stiffness Progressive stiffness

Mental retardationMental retardation

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Prevention Prevention Genetic counseling: important for parents Genetic counseling: important for parents with a family history of Hurler syndromewith a family history of Hurler syndrome

Prenatal diagnosis:Prenatal diagnosis:

An amniocentesis in the amniotic fluid are An amniocentesis in the amniotic fluid are then cultured and the a-L-iduronidase then cultured and the a-L-iduronidase activity in the cells is determined.activity in the cells is determined.

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SymptomsSymptoms

Short statureShort stature

Severe mental retardationSevere mental retardation

Thick, coarse facial features with low nasal Thick, coarse facial features with low nasal bridgebridge

Full lips with a thick, large tongue Full lips with a thick, large tongue

Increased body hair (hirsutism) Increased body hair (hirsutism)

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SymptomsSymptoms

Umbilical herniaUmbilical hernia

Deafness Deafness

Stiffness (in joints) Stiffness (in joints)

Shortness of breath Shortness of breath

Abnormal bones of spine and Abnormal bones of spine and claw hand claw hand

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MPS: SignsMPS: SignsHepatomegalyHepatomegaly

SplenomegalySplenomegaly

Enlarged tongue Enlarged tongue

Retinal pigmentation Retinal pigmentation

Hip dislocationHip dislocation

KyphosisKyphosis

Heart murmursHeart murmurs

Heart valve damage from Heart valve damage from thickeningthickening

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Tests that may indicate the Tests that may indicate the syndromesyndrome

Increased excretion of dermatan Increased excretion of dermatan sulfate and heparan sulfate in the sulfate and heparan sulfate in the urine urine

Absence of lysosomal alpha-L-Absence of lysosomal alpha-L-iduronidase (in cultured iduronidase (in cultured fibroblasts)fibroblasts)

Culture of cells from amniotic fluid Culture of cells from amniotic fluid obtained by amniocentesis for obtained by amniocentesis for enzyme testing (prenatal testing) enzyme testing (prenatal testing)

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Tests that may indicate the Tests that may indicate the syndromesyndrome

Abnormal histological Abnormal histological staining of white blood cells staining of white blood cells called called metachromasia metachromasia

X-ray of the skeleten X-ray of the skeleten

X-ray of the spineX-ray of the spine

X-ray of the chestX-ray of the chest

ECGECG

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Hunter syndrome type IIHunter syndrome type II

((Sulpho-idoronide sulphatase Sulpho-idoronide sulphatase deficiencydeficiency ) )

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Hunter syndrome Hunter syndrome type IItype II

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Hunter syndrome type IIHunter syndrome type II

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Hunter syndrome type IIHunter syndrome type II ((Sulpho-idoronide sulphatase Sulpho-idoronide sulphatase

deficiencydeficiency ) )X-linkedX-linkedCoarse, thick, facial featuresCoarse, thick, facial featuresProgressive stiffness Progressive stiffness decreased mental development decreased mental development Hepatomegaly Hepatomegaly (liver enlargement) (liver enlargement) Splenomegaly Splenomegaly (spleen (spleen enlargement) enlargement) Abnormal bone x-raysAbnormal bone x-rays

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Sanfilippo syndrome Sanfilippo syndrome type IIItype III

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Sanfilippo syndrome Sanfilippo syndrome type IIItype III

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Sanfilippo syndrome type IIISanfilippo syndrome type III

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Sanfilippo syndrome type IIISanfilippo syndrome type III

DefinitionDefinition

Sanfilippo syndrome is one of the Sanfilippo syndrome is one of the hereditary mucopolysaccharide hereditary mucopolysaccharide storage diseasesstorage diseasesit is characterized by the absence of it is characterized by the absence of one of several enzymes one of several enzymes These enzymes help the body get rid These enzymes help the body get rid of a substance normally found outside of a substance normally found outside of our cells called a of our cells called a mucopolysaccharidemucopolysaccharideThis substance is called heparan This substance is called heparan sulfate, and in Sanfilippo syndrome, sulfate, and in Sanfilippo syndrome, large amounts of it are excreted in the large amounts of it are excreted in the urine urine

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Alternative Names Alternative Names Mucopolysaccharidosis type Mucopolysaccharidosis type

IIIIIIsubtypes A - B – C - Dsubtypes A - B – C - D

Type IIIA: heparan sulfate Type IIIA: heparan sulfate sulfatase deficiencysulfatase deficiencyType IIIB: N-Type IIIB: N-

acety-glucos-aminidase-acety-glucos-aminidase-deficiencydeficiencyType IIID: N-acetyl-glucos-Type IIID: N-acetyl-glucos-amine-6-sulfate sulfatase amine-6-sulfate sulfatase deficiencydeficiency

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Sanfilippo Sanfilippo syndromesyndrome Causes Causes

an autosomal recessive traitan autosomal recessive trait

It is possibly the most It is possibly the most common of the common of the mucopolysaccharide storage mucopolysaccharide storage diseasesdiseases

It has a relatively late It has a relatively late onset rather than during the onset rather than during the first year of lifefirst year of life

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CausesCausesCoarse, thick, facial featuresCoarse, thick, facial features

Prominent dark eyebrowsProminent dark eyebrows

Progressive stiffness Progressive stiffness

gait disturbances gait disturbances

speech disturbances speech disturbances

decreased mental decreased mental development that progresses development that progresses to severe mental retardationto severe mental retardation

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PreventionPreventionGenetic counseling: important Genetic counseling: important for prospective parents with a for prospective parents with a family history of Sanfilippo family history of Sanfilippo syndromesyndrome

Prenatal diagnosis:Prenatal diagnosis:An amniocentesis in the An amniocentesis in the amniotic fluid are then cultured amniotic fluid are then cultured and the enzyme activity in the and the enzyme activity in the cells is determined.cells is determined.

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SymptomsSymptomsFamily history of Sanfilippo syndrome Family history of Sanfilippo syndrome May have normal growth during first May have normal growth during first few years, but final height is below few years, but final height is below average average Delayed development followed by Delayed development followed by deteriorating mental status deteriorating mental status Deterioration of gait Deterioration of gait Coarse facial features Coarse facial features Full lips Full lips Heavy eyebrows that meet in the Heavy eyebrows that meet in the middle of the face above the nose middle of the face above the nose Diarrhea Diarrhea Stiff joints that may not extend fully Stiff joints that may not extend fully

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Sanfilippo syndromeSanfilippo syndrome Signs and testsSigns and tests

Hepatomegaly (liver Hepatomegaly (liver enlargement) enlargement) Splenomegaly (spleen Splenomegaly (spleen enlargement) enlargement) Corneas Corneas clearclear Echocardiogram may show Echocardiogram may show thickened heart thickened heart Abnormal bone x-rays such as Abnormal bone x-rays such as thickened skull and oval thickened skull and oval vertebrae vertebrae

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Sanfilippo syndromeSanfilippo syndrome Signs and testsSigns and tests

SeizuresSeizures

mental retardation mental retardation

Activities of one of the enzymes Activities of one of the enzymes may be low in fibroblast skin cells may be low in fibroblast skin cells

Urine may have increased heparan Urine may have increased heparan sulfate sulfate

Abnormal pathological staining Abnormal pathological staining character of white blood cells called character of white blood cells called metachromasiametachromasia

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Features and CharacteristicsFeatures and Characteristics children with Sanfilippo children with Sanfilippo

syndromesyndrome

Occasional enlarged headOccasional enlarged head

Coarse facial features Coarse facial features

Coarse hair Coarse hair

Excessive hair growth Excessive hair growth

Joint stiffness Joint stiffness

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Sanfilippo syndromeSanfilippo syndromeSevere diarrhea or constipation Severe diarrhea or constipation Severe hearing loss Severe hearing loss Hyperactivity Hyperactivity Aggressive and destructive behavior Aggressive and destructive behavior Poor attentionPoor attentionPhysical aggression Physical aggression Speech and language delay Speech and language delay Sleep disturbance Sleep disturbance Severe intellectual impairment most Severe intellectual impairment most often before 6 years of age often before 6 years of age Mild growth retardation Mild growth retardation Vision impairment Vision impairment

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Morquio syndrome Morquio syndrome Type IVType IV

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Morquio syndrome Morquio syndrome Type IVType IV Skeletal abnormality - hand

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Skeletal abnormality: flattened Skeletal abnormality: flattened vertebraevertebrae

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Morquio syndrome Morquio syndrome Type IVType IV

subtypes A & Bsubtypes A & B

Type IVA: Galactose-6- Type IVA: Galactose-6- sulfatase deficiencysulfatase deficiency

Type IVB: Type IVB: Galactosidase Galactosidase deficiencydeficiency

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Features and Features and CharacteristicsCharacteristics

children with Morquio syndromechildren with Morquio syndrome Joint stiffnessJoint stiffnessMild growth retardationMild growth retardationStiff joints that may not Stiff joints that may not extend fully extend fully Without mental retardation !Without mental retardation !Abnormal bone x-raysAbnormal bone x-rays– X-ray of the skeleten X-ray of the skeleten – X-ray of the spineX-ray of the spine– X-ray of the chestX-ray of the chest

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PreventionPrevention

Genetic counseling: important for Genetic counseling: important for prospective parents with a family prospective parents with a family history of Morquio syndromehistory of Morquio syndrome

Prenatal diagnosis:Prenatal diagnosis:An amniocentesis in the amniotic An amniocentesis in the amniotic fluid are then cultured and the fluid are then cultured and the enzyme activity in the cells is enzyme activity in the cells is determined.determined.

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Maroteaux-Lamy Maroteaux-Lamy syndrome syndrome Type VType V

(N-Acetyl-galactose-amin-(N-Acetyl-galactose-amin-4-sulfatase (Arylsulfatase 4-sulfatase (Arylsulfatase

B)B)

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Maroteaux-Lamy syndrome Maroteaux-Lamy syndrome TypeVTypeV

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Maroteaux-Lamy syndrome TypeVMaroteaux-Lamy syndrome TypeV

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Features and Features and CharacteristicsCharacteristics Maroteaux-Lamy Maroteaux-Lamy

syndromesyndrome

Coarse facial Coarse facial featuresfeatures

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TreatmentTreatmentAt the present time, there is no cure At the present time, there is no cure for MPS disorders. for MPS disorders. Enzyme replacement therapy and Enzyme replacement therapy and gene therapy are the two treatments gene therapy are the two treatments that researchers have been focusing that researchers have been focusing on to eventually cure MPS diseases. on to eventually cure MPS diseases. There are a number of research There are a number of research institutions around the world institutions around the world working on finding a cure for the working on finding a cure for the MPS diseases including facilities in MPS diseases including facilities in the United States, Canada, England, the United States, Canada, England, and Australia.and Australia.