Patau syndrome & Edwards syndrome Manifestations
Trisomy 13 (Patau syndrome) is the third most common autosomal trisomy identified in liveborn infants, and the most severe. Affected children typically die within the first week of life, with only 5% surviving the first six months. In the majority of trisomy 13 infants cytogenetic studies demonstrate nondisjunction (47XX, +13); this chromosomal abnormality arises during maternal meiosis I and is associated with advanced maternal age.
The prominent phenotypic features of trisomy 13 are associated with an early defect in prechordal mesoderm development. As a result, the midface, eye, and forebrain are most markedly affected. The clinical manifestations of Patau syndrome include the abnormalities categorized by system below.
1. Head and neck: severe cleft lip and/or palate microphthalmia or anophthalmia, coloboma, cyclops, malformed or absent nose, deafness, scalp defects (aplasia cutis)
2. CNS: severe mental retardation microcephaly, holoprosencephaly (failure of brain to divide into hemispheres) absent olfactory nerve or bulb, neural tube defects
3. Extremities: polydactyly, rocker-bottom feet
4. Cardiac: PDA, atrial septal defect, ventricular septal defect
5. Renal: polycystic kidney disease
6. Gastrointestinal: abdominal wall defects associated with omphalocele or umbilical hernia, pyloric stenosis.
Clinical manifestations of trisomy 18 (Edwards syndrome) include
prominent occiput micrognathia,
small mouth low-set and malformed ears, and rocker-bottom feet.
Clenched hands with the index finger overriding the middle finger
and the fifth finger overriding the fourth finger are characteristic for this condition.
Meckel’s diverticulum and malrotation are common gastrointestinal abnormalities.
The prominent phenotypic features of trisomy 13 are associated with an early defect in prechordal mesoderm development. As a result, the midface, eye, and forebrain are most markedly affected. The clinical manifestations of Patau syndrome include the abnormalities categorized by system below.
1. Head and neck: severe cleft lip and/or palate microphthalmia or anophthalmia, coloboma, cyclops, malformed or absent nose, deafness, scalp defects (aplasia cutis)
2. CNS: severe mental retardation microcephaly, holoprosencephaly (failure of brain to divide into hemispheres) absent olfactory nerve or bulb, neural tube defects
3. Extremities: polydactyly, rocker-bottom feet
4. Cardiac: PDA, atrial septal defect, ventricular septal defect
5. Renal: polycystic kidney disease
6. Gastrointestinal: abdominal wall defects associated with omphalocele or umbilical hernia, pyloric stenosis.
Clinical manifestations of trisomy 18 (Edwards syndrome) include
prominent occiput micrognathia,
small mouth low-set and malformed ears, and rocker-bottom feet.
Clenched hands with the index finger overriding the middle finger
and the fifth finger overriding the fourth finger are characteristic for this condition.
Meckel’s diverticulum and malrotation are common gastrointestinal abnormalities.
Caloric reflex test
When you put Cold Water in an ear the nystagmus is towards the lesion with quick phase to the opposite side.
When you Put Warm Water in an ear the nystagmus is to the opposite side with quick phase to the same side.
COWS: Cold Opposite, Warm Same.
Cold water = FAST phase of nystagmus to the side Opposite from the cold water filled ear
Warm water = FAST phase of nystagmus to the Same side as the warm water filled ear
In other words: Contralateral when cold is applied and ipsilateral when warm is applied
Link :
http://www.youtube.com/watch?v=4NDOQnRMLIs
When you Put Warm Water in an ear the nystagmus is to the opposite side with quick phase to the same side.
COWS: Cold Opposite, Warm Same.
Cold water = FAST phase of nystagmus to the side Opposite from the cold water filled ear
Warm water = FAST phase of nystagmus to the Same side as the warm water filled ear
In other words: Contralateral when cold is applied and ipsilateral when warm is applied
Link :
http://www.youtube.com/watch?v=4NDOQnRMLIs
Differential diagnosis of elevated CPK (Creatine phosphokinase)
Differential diagnosis of elevated CPK
- HMG Co-A reductase inhibitors (statins),
- Autoimmune disease (polymyositis / dermatomyositis)
- Muscular dystrophies (like Duchenne muscular dystrophy).
- Hypothyroid myopathy.
Associations of autosomal and sex chromosomal-inherited disorders
A variety of autosomal and sex chromosomal-inherited disorders are associated with developmental cardiac and/or aortic defects or cardiac pathology. The major associations are as follows:
1. Down syndrome: endocardial cushion defects (ostium primum ,ASD, regurgitant AV valves)
2. DiGeorge syndrome: tetralogy of fallot and aortic arch anomalies
3. Friedreich’s ataxia: hypertrophic cardiomyopathy
4. Marfan syndrome: cystic medial necrosis of the aorta
5. Tuberous sclerosis: valvular obstruction due to cardiac rhabdomyomas
6. Turner’s syndrome: coarctation of the aorta.
1. Down syndrome: endocardial cushion defects (ostium primum ,ASD, regurgitant AV valves)
2. DiGeorge syndrome: tetralogy of fallot and aortic arch anomalies
3. Friedreich’s ataxia: hypertrophic cardiomyopathy
4. Marfan syndrome: cystic medial necrosis of the aorta
5. Tuberous sclerosis: valvular obstruction due to cardiac rhabdomyomas
6. Turner’s syndrome: coarctation of the aorta.
Proto-oncogenes (tumor promoters) versus Anti-oncogenes (tumor suppressors)
Abnormal growth of neoplastic cells can arise secondary to mutation of either proto-oncogenes or anti oncogenes. Proto-oncogenes stimulate cell proliferation. Overexpression or amplification of a proto-oncogene leads to increased cellular proliferation and neoplastic growth. Anti-oncogenes, in contrast, are tumor suppressors in that they inhibit cellular proliferation. Inactivation of anti-oncogenes contributes to tumor development.
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