About roberts sc-phocomelia syndrome
What is roberts sc-phocomelia syndrome?
Phocomelia syndrome (PS) is a rare birth defect that causes severe birth defects, especially of the upper limbs. The bones of the arms, and in some cases other appendages, may be extremely shortened and even absent. The fingers of the hands may be fused. An extreme case results in the absence of the upper bones of both the arms and legs so that the hands and feet appear attached directly to the body. This is called tetraphocomelia.
This disorder, PS, may be genetically transmitted within families as an autosomal recessive trait or may be the result of spontaneous (sporadic) changes in the gene. Because the signs of the disorder so closely mimic those caused by the ingestion of thalidomide by pregnant women, the term "pseudo-thalidomide" is frequently used.
What are the symptoms for roberts sc-phocomelia syndrome?
The symptoms associated with Roberts syndrome vary widely from person to person even among members of the same family. Most infants experience growth deficiencies and have abnormalities of the limbs and Craniofacial region. Infants with Roberts syndrome often experience life-threatening complications early in infancy.
Affected infants may experience growth deficiencies before and after birth. Intellectual disability is a variable finding that occurs in approximately 50 percent of affected children.
Limb abnormalities are common in infants with Roberts syndrome and may range from underdeveloped bones in the arms and legs (hypomelia) to complete absence of all four limbs (tetraphocomelia). The arms are usually more severely affected than the legs.
Additional abnormalities may affect the arms and legs including permanent fixation (contracture) of various joints, especially the knees and elbows. The number of fingers and/or toes may be reduced and the fifth fingers may be in a fixed laterally deviated position (clinodactyly). Webbing of the finger and toes (syndactyly) may also be present. Infants with Roberts syndrome may also have a form of club foot where the heel of the foot may be elevated and turned outward away from the body (talipes equinovalgus).
Infants with Roberts syndrome also have a variety of Craniofacial abnormalities including a small, Broad head (microbrachycephaly); an abnormal groove in the upper lip (cleft lip) with or without incomplete closure of the roof of the mouth (cleft palate); a flattened nose with small wings; an abnormally Small jaw (micrognathia); sparse, silvery hair; and malformed, low-set ears that often lack lobes. Some infants may experience premature fusion of the fibrous joints (cranial sutures) between certain bones in the skull (craniosynostosis). Affected infants may have eye (ocular) abnormalities including Widely spaced eyes (hypertelorism); unusually Small eyes (microphthalmia); cloudy corneas; and bulging or Prominent eyes (proptosis) due to shallow eye cavities (orbits). In some children, the Whites of the eyes may be blue (blue sclera) and increased pressure within the eyeball (glaucoma) may also be present.
Some infants with Roberts syndrome may have one or more pink or dark red irregularly shaped patches of skin (hemangiomas) on the face caused by dense collections of small blood vessels (capillaries).
Infants with Roberts syndrome often have abnormalities affecting the genitourinary system. Males may have the urinary opening located on the underside of the penis (hypospadias) and the testicles may fail to descend into the scrotum (cryptorchidism). Females may have a malformed uterus with horn-like branches (bicornuate uterus).
Less common symptoms associated with Roberts syndrome include malformed kidneys, an abnormal increase in cerebrospinal fluid resulting in enlargement of the skull (hydrocephalus), Paralysis of cranial nerves, seizures, Heart defects and a decreased number of blood platelets (thrombocytopenia).
What are the causes for roberts sc-phocomelia syndrome?
Roberts syndrome is caused by disruptions or changes of the ESCO2 (establishment of cohesion 1 homolog 2) gene located on the short arm (p) of chromosome 8 (8p21.1). Chromosomes, which are present in the nucleus of human cells, carry the genetic information for each individual. Pairs of human chromosomes are numbered from 1 through 22, and an additional 23rd pair of sex chromosomes, which include one X and one Y chromosome in males and two X chromosomes in females. Each chromosome has a short arm designated “p” and a long arm designated “q”. Chromosomes are further subdivided into many regions, bands and sub-bands that are numbered. For example, “chromosome 8p21.1” refers to region 2, band 1, sub-band 1 on the short arm of chromosome 8. The numbered bands specify the location of the thousands of genes that are present on each chromosome.
There are certain complex chromosomal abnormalities which are distinguishing features of Roberts syndrome. Most affected individuals have premature centromere separation of various chromosomes, especially chromosomes 1, 9, and 16, a phenomenon often referred to as “puffing.” The centromere is the center of a chromosome located between the long and short arms of a chromosome. The characteristic “puffing” abnormality is apparent in mitosis, the process in which a cell divides ultimately forming two cells identical to the original.
Roberts syndrome is inherited in an autosomal recessive pattern in most families. Genetic diseases of this type are determined by two abnormal genes, one received from the father and one from the mother.
Recessive genetic disorders occur when an individual inherits an abnormal gene from each parent. If an individual receives one normal gene and one abnormal gene for the disease, the person will be a carrier for the disease, but usually will not show symptoms. The risk for two carrier parents to both pass the abnormal gene and, therefore, have an affected child is 25% with each pregnancy. The risk to have a child who is a carrier, like the parents, is 50% with each pregnancy. The chance for a child to receive normal genes from both parents is 25%. The risk is the same for males and females.
It is also possible that a new mutation in an autosomal dominant gene could be the cause of Roberts syndrome is some families. Dominant genetic disorders occur when only a single copy of an abnormal gene is necessary to cause a particular disease. The abnormal gene can be inherited from either parent or can be the result of a mutated (changed) gene in the affected individual. The risk of passing the abnormal gene from an affected parent to an offspring is 50% for each pregnancy. The risk is the same for males and females.
What are the treatments for roberts sc-phocomelia syndrome?
The treatment of Roberts syndrome is directed toward the specific symptoms that are apparent in each individual. Treatment may require the coordinated efforts of a team of specialists. Pediatricians, surgeons, cardiologists, neurologists, eye specialists, and other health care professionals may need to systematically and comprehensively plan an affected child’s treatment.
Individuals with Roberts Syndrome may benefit from surgery for facial and limb defects. Prosthetic devices can also reduce problems associated with missing limbs.
Genetic counseling is recommended for affected individuals and their families. Other treatment is symptomatic and supportive.
What are the risk factors for roberts sc-phocomelia syndrome?
Roberts syndrome affects males and females in equal numbers. The incidence of Roberts syndrome is unknown.
Is there a cure/medications for roberts sc-phocomelia syndrome?
Roberts Sc-phocomelia Syndrome is a rare autosomal recessive condition where the onset of prenatal growth is carried over into the postnatal period. It is identified with extreme malformations, craniofacial abnormalities, and impaired cognitive development, including cardiac and renal anomalies. A cause of this can be disruptions and changes of the gene situated on the shorter arm (p) of chromosome 8.
Cure/medications for Roberts Sc-phocomelia Syndrome
Misfortunes state that there is no identified cure for this symptom. The best to expect, realistically, is for the affected person to live into adulthood.
Approved drugs for Roberts Sc-phocomelia Syndrome are as follows:
1. Hydroxyurea (approved)
2. Busulfan (approved, investigational)
3. Fludarabine (approved)
4. Prednisone (approved)
5. Tacrolimus (approved, investigational)
1. Surgery for cleft lip and cleft palate
2. Surgery for readjustment of abnormalities of the limbs
3. Surgery for improvement in prehensile hand movement development
Growth deficiencies and have abnormalities of the limbs and craniofacial region,Underdeveloped bones in the arms and legs (hypomelia),Permanent fixation (contracture) of various joints, especially the knees and elbows,Craniofacial abnormalities including a small, broad head (microbrachycephaly),An abnormal groove in the upper lip (cleft lip) with or without incomplete closure of the roof of the mouth (cleft palate),Aflattened nose with small wings; an abnormally small jaw (micrognathia),Sparse, silvery hair,Malformed, low-set ears
Growth delays before and after birth,Malformations of the arms and legs,Distinctive abnormalities of the skull and facial (craniofacial) region,Intellectual disability