This is a condition characterized by the short stature as the result of growth problem that begins before the birth of the infant (intrauterine growth retardation). Also known as ear, patella-short stature syndrome, it presents the small ears (microtia), absent or small knee caps (patellae) and short stature. The intelligence of the affected individuals is considered to be average but the life expectancy is based on the severity of the condition. There are several types of this syndrome that are distinguished by the specific gene involved. As this is a rare condition, the exact prevalence of this syndrome is not known.
Causes
Meier-Gorlin syndrome can develop as the result of the mutation in one of the several genes identified as ORC1, ORC4, ORC6, CDT1 and CDC6 which produce a group of proteins called the pre-replication complex. This complex is essential for the regulation of DNA replication before the cells divide. This pre-replication complex binds to a region of the DNA allowing for the copying of the DNA which occurs once per cell division. The genetic mutation in any of one of the genes can affect the normal development of the pre-replication complex and results in the development of the symptoms associated with this syndrome. Meier-Gorlin syndrome is inherited in an autosomal recessive pattern meaning both the copies of the gene in each cell are defective. The parents of the affected individual are each the carrier of the defective gene and don’t necessarily exhibit the symptoms associated with this condition.
Symptoms
The congenital features can include the small ears, absent or small knee caps and short stature. The skeletal malformations can include unusually slender ribs and long bones, deformed ribs and dislocation of the elbows. Most of the cases are the result of the slow growth rate during fetal development which can cause the low birth weights. The feeding difficulties and the failure to thrive can also result in the short stature. They can also present arched roof of the mouth (palate), abnormally small jaw, droopy eyelids, small head (microcephaly) and small mouth.
Diagnosis
The diagnosis is possible at the birth of the infant based on the physical examination, medical history and various specialized tests. The presence of the microtia and small or absent knee cap can assist with the initial diagnosis of this syndrome. The ultrasonography or the X-ray can evaluate the bone development and the careful examination of the bone system of the affected individual can help with the diagnosis. The genetic testing can confirm the diagnosis by identifying the mutation responsible for developing this syndrome.
Treatment
The treatment is based on the symptoms that are evident. The treatment plan needs to be devised with the coordinated efforts of various specialists such as orthopedists, audiologist, pediatricians and surgeons. The jaw abnormalities can be treated with the maxillofacial surgery. These affected children’s feeding and growth patterns should be carefully monitored as they often present a problem with the weight gain. The respiratory tract infection is one of the common complications associated with this condition that can develop in early infancy and hence treatment for this should be initiated soon as possible. Additional treatment options can include physical therapy, social or vocational services. In some of the cases, the affected individuals and their family can benefit from a genetic counseling.
References
https://rarediseases.org/rare-diseases/ear-patella-short-stature-syndrome/
https://rarediseases.info.nih.gov/diseases/2033/meier-gorlin-syndrome
https://ghr.nlm.nih.gov/condition/meier-gorlin-syndrome#statistics