More about the syndromes assocaited with polydactyly:
Ellis-van Creveld syndrome (chondroectodermal dysplasia)
* Stillbirth (common)
* Death in early infancy (common)
* Short extremities, especially forearm and lower leg
* Hair abnormalities: sparse, absent, fine texture
* Cleft lip or palate
* Tooth abnormalities:
o Peg teeth
o Widely spaced teeth
o Teeth present at birth (natal teeth )
o Teeth - delayed or absent formation
* Nail abnormalities: absent nails, deformed nails
* Joint abnormalities: limited range of motion
* Extra fingers (polydactyly )
* Epispadias or an undescended testicle (cryptorchidism)
* Congenital heart defects such as a hole in the heart atrial septal defect (ASD)
Carpenter syndrome belongs to a group of rare genetic disorders known as “acrocephalopolysyndactyly” (ACPS) disorders. All forms of ACPS are characterized by premature closure of the fibrous joints (cranial sutures) between certain bones of the skull (craniosynostosis), causing the top of the head to appear pointed (acrocephaly); webbing or fusion (syndactyly) of certain fingers or toes (digits); and/or more than the normal number of digits (polydactyly). Carpenter syndrome is also known as ACPS type II.
Carpenter syndrome is typically evident at or shortly after birth. Due to craniosynostosis, the top of the head may appear unusually conical (acrocephaly) or the head may seem short and broad (brachycephaly). In addition, the cranial sutures often fuse unevenly, causing the head and face to appear dissimilar from one side to the other (craniofacial asymmetry). Additional malformations of the skull and facial (craniofacial) region may include downslanting eyelid folds (palpebral fissures); a flat nasal bridge; malformed (dysplastic), low-set ears; and a small, underdeveloped (hypoplastic) upper and/or lower jaw (maxilla and/or mandible).
Individuals with Carpenter syndrome may also have unusually short fingers and toes (brachydactyly); partial fusion of the soft tissues (cutaneous syndactyly) between certain digits; and the presence of extra (supernumerary) toes or, less commonly, additional fingers (polydactyly). In some instances, additional physical abnormalities are present, such as short stature, structural heart malformations (congenital heart defects), mild to moderate obesity, weakening in the abdominal wall near the navel through which the intestine may protrude (umbilical hernia), or failure of the testes to descend into the scrotum (cryptorchidism) in affected males. In addition, many individuals with the disorder are affected by mild to moderate mental retardation. However, intelligence is normal in some instances. Carpenter syndrome is usually inherited as an autosomal recessive trait.
Trisomy 13 occurs in about 1 out of every 5,000 live births. It is a syndrome with multiple abnormalities, many of which are not compatible with life. More than 80% of children with trisomy 13 die in the first month.
Trisomy 13 is associated with multiple abnormalities, including defects of the brain that lead to seizures, apnea, deafness, and eye abnormalities.
The eyes are small with defects in the iris (coloboma ). Most infants have a cleft lip and cleft palate, and low-set ears. Congenital heart disease is present in approximately 80% of affected infants. Hernias and genital abnormalities are common.
Symptoms Return to top
* Mental retardation, severe
* Small head (microcephaly)
* Scalp defects (absent skin)
* Small eyes (microphthalmia)
* Cleft lip and/or palate
* Eyes close set (hypotelorism) -- eyes may actually fuse together into one
* Iris defects (coloboma)
* Pinna abnormalities and low set ears
* Simian crease
* Extra digits (polydactyly)
* Hernias: umbilical hernia, inguinal hernia
* Undescended testicle (cryptorchidism)
* Skeletal (limb) abnormalities
The infant may have a single umbilical artery at birth. There are often signs of congenital heart disease:
* Ventricular septal defect (VSD)
* Atrial septal defect (ASD)
* Patent ductus arteriosus (PDA)
* Abnormal placement of the heart (dextroversion -- the heart is placed toward the right side of the chest instead of the left)
Rubinstein-Taybi syndrome is a genetic disease characterized by mental deficiency, broad thumbs and toes, short stature, and characteristic facial features.
Rubinstein-Taybi syndrome (RTS) is a rare condition, affecting about 1 in 125,000 people. The gene involved in RTS, which is called CREB binding protein (CREBBP), was identified in 1995.
Most patients have mutations in the gene, resulting in an abnormal CREB binding protein. About 10% of patients, typcially with more severe problems, have an outright deletion of the gene and they do not make any of the protein.
Most cases are sporadic and likely due to a new mutation occurring during fetal development, which was not passed on by either parent. However, in some cases, it is inherited in an autosomal dominant fashion, which means that if one parent passes on the defective gene, the child will be affected.
The classic feature is broad thumbs and great toes, but typically there is also short stature, unusual face, low-set ears, port-wine-stain, undescended testicles in the male, and downward slant of the eyes.
* Broad thumbs and great toes
* Slow development of both cognitive and motor skills with low muscle tone
* Mental retardation
* Short stature that is noticeable after birth
* Excess hair on body (hirsutism)
* Heart defects possibly requiring surgery (about 40% of patients)
In addition to growth retardation and developmental delay, many different malformations have been described in SLO/RSH. The most common defects are:
- Microcephaly (small head)
- Extra fingers or toes
- Apparently low-set ears
- Small, upturned nose
- Webbing between 2nd and 3rd toes
- Abnormal palmar creases (usually single)
- Cleft palate
- Hypospadias (genital malformation in boys)
- Undescended testicles
- Blepharoptosis (drooping eyelids)
- Heart defects
- Micrognathia (small chin)
- Pyloric stenosis
- Short thumbs
- Hirschsprung disease (absent nerves in colon)
Laurence-Moon-Biedl syndrome is an autosomal recessive condition characterised by:
* mental retardation
* retinitis pigmentosa
* spastic paraplegia
* renal anomalies (calyceal cysts, clubbing or diverticula; fetal lobulation)
Asphyxiating thoracic dystrophy
Asphyxiating thoracic dystrophy is a very rare form of congenital dwarfism affecting the development of the bone structure, particularly of the chest (thorax) but also of the legs and arms. Typical, major characteristics include failure of the rib cage to develop correctly, kidney problems (renal failure due to polycystitis), and shortened bones of the arms and legs.