Dysplasia Made Easy

Skeletal Dysplasia Made Easy Dr. Omneya Nagy ElmakhzangySpecial Fetal Care Unit Ain Shams University

Symmetrical

Achondrogenesis KEY Finding : 1- Severe micromelia (shortened bones)2- Hypomineralization (bone unusally anechoic)3- Fetal hydrops + hydramnios (late)

TypesHint : All involve extremely short long bone and severity is according to involvement of calvarium and vertebral column.Type 1: Calvarium and Vertebral column severly hypomineralized.Type 2 : Calvarium is ossified but veterbral column may or may not be ossifiedType 3: Mildest form where hypomineralization only includes cervical and caudal vertebrae

Prognosis All 3 types are lethal at or before birth

Recurrence is 1:4 in type1 and is a new Dominant mutation in types 2 and 3 .

Thanatophoric DysplasiaFeatures:1- Short long bones well below the 3rd percentile 2- Characteristic thickening of the metaphysis3-short splayed fingers (trident)4- Short ribs 5- markedly small thorax 6- Depressed nasal bridge + frontal bossing

Prognosis LETHAL Recurrence is low (dominant sporadic condition)

Trunchal Champagne Cork

Campomelic DysplasiaFeatures mainly in the lower limb :1- Short bowed femur , tibia and Fibula + marked Talipes 2- The whole lower limb is bowed inwards hint the name (Campomelia) derived from a greek word campo or campto meaning BENT.3- marked association with soft tissue involvement (cardiac, renal and Brain)

Prognosis of the cases die during neonatal period due to associated pulmonary hypoplasia the prognosis is mainly dependent on other organ involvement Recurrence is around 5%

Osteogenesis imperfecta Poor bone mineralizationTypes 1-4Most common types is type 2Short, hypomineralized crumpling bones with multiple fractures Criteria of Diagnosis : 1- Multiple fractures , 2-hypoechoic skull , 3- Femur length more than 3 SD below G.A

PrognosisWorst types in the prognostic views are type 2a,c and type 3 and type 2 b is intermediate all causing poor bone mineralization Types 2a,c and type3 are lethal and 2b is often lethal Types 1 and 4 are rarely diagnosed in IU life and usually symptomatize later in post natal life

Hypophosphatasia Decreased bone mineralization due to deficiency in alkaline phosphataseA spectrum of Severity from a lethal form close to Osteogensis imperfecta with more severe angulation in the fractures to a milder forms that can be diagnosed later in early childhood.

Diagnosis Mainly by U/S finding of hypomineralization of bones and confirmed by biochemical testing to the Amniotic fluid for Alkaline Phosphatase , radiography , or genetic testing of the parents.

Prognosis Autosomal recessive types are lethal Autosomal dominant types tend to be milder and improve with age

Homoygous Achondroplasia Result from two parents who are heterogygous achophondroplasia and the fetuses usually perish early in gestation and so is rarely deen

MODERATE SYMMETRICAL

Asphyxiating thoracic Dystrophy (Jeune)The main feature in this condition is a small chest in a high risk family limb shortening is variable and may not be apparent till 3rd trimester Soft tissue involvement renal , hepatic and pulmonary with post axial polydactyly.

Prognosis 70% of live born die from RDSSurvivors are small in size and suffer from the systemic complications associated with the disorder , intelligence is normal though

Short ribbed polydactyly SyndromesSmall Narrow thorax + short limbs + polydactyly + specific feature for each type

Type 1 : (SALDINO- NOONAN Syndrome)Micromelia with pointed ends in long bonesUrogenital and anorectal anomalies

Type 2 (MAJEWKSKI SYNDROME)- Median cleft lip/palate and disproportionally short tibiae

Prongnosis LETHAL Secondary to respiratory faliure

Chondrodermal Dysplasia (ELLIS_VAN CREVELD SYNDROME) Upper limb Mesomelia (Short radius and ulna) + polydactyly in hands + small thoraxHighly Associated Congenital heart disease as ASD once diagnosed fetal Echo is recommended

Prognosis

Survivors have normal intelligence but final height (105-150 cm)Inheritance is autosomal recessive recurrence of 25%

Diastrophic DysplasiaRhizomelic shortening ( shortening of the proximal long bones (humerus and femur) +bowing + hitchhicker thumb + talipesIdentification of a normal thumb can help exclude diagnosis

Prognosis A significant number die of respiratory faliure and pneumonia Those who survive have normal intellect but progressive handicap.

Chondrodysplasia Punctata X-linked dominant : seen in females and lethal in heterozygous malesX-linked recessive : moderate shortening of long bones + EPIPHESYEAL ECHOGENICITES affected intellect , heterozygous female carriers are clinically free and rather short.Rhizomelic form : humerus is more affected

Prognosis Many Newborn die of respiratory faliure survivors fail to thrive with microcephaly

Kniest DysplasiaModerately short dumbbell- shaped long bones + restricted joint mobility + depressed nasal bridge+ platyspondyly .

Affected children have normal intellect but short stature and limited joint mobility

Heterozygous achondroplasia (Dwarfism) The most well recognized dysplasia in general population , with short stature but well integrated members of the society.Acromesomelic limb shortening + stubby abducted fingers (trident hand) + wide prominent forehead (frontal bossing) + hypertelorism

Short long Bones : Asymmetrical

Isolated limb ReductionAsymmetrical reduction of a limb or part of a limbMajorly are non genetic but can occur as a part of genetic syndrome or chromosomal abnormality. Karyotyping and thorough sonography is recommended.With no other associations prosthestics and orthopedic surgery function and shape can be restored

Roberts Syndrome (pseudothalidomide Syndrome)All 4 limbs affected (tetraphocomelia)+ median facial clefting+ microcephaly + talipes+ extremely short of missing fingers or toes .Other assciated anomalies include hydrocephalus , encephalocele , renal anomalies.

High perinatal mortality Severe IUGR Survivors are profoundly mentally retarded

Femur-Fibula-Ulna SyndromeFrom its name the Syndrome is mainly affection of femur and fibula with varying degrees of ulnar affection.

Holt-Oram SyndromeUpper limb and limb girdle reductions A cardinal feature is association with congenital heart disease More in females and more on left than right.A Dominant condition 50% of affected inndividuals offsprings will be affected

Thrombocytopenia absent radius symdromeTAR , could be confirmed by bilateral radial aplasia/hypoplasia .Thrombocytopenia is a marker of heampoietic abnormality.Autosomal recessive condition with 25% recurrence

Cleidocranial Dystosis Hypoplastic claviclesDe novo presentations are usually missed as clavicle is not routinely surveyed Affected skull mineralization

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