Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
Dr. Perlstein received his Medical Degree from the University of Cincinnati and then completed his internship and residency in pediatrics at The New York Hospital, Cornell medical Center in New York City. After serving an additional year as Chief Pediatric Resident, he worked as a private practitioner and then was appointed Director of Ambulatory Pediatrics at St. Barnabas Hospital in the Bronx.
Achondroplasia is inherited as an autosomal dominant trait whereby only a single copy of the abnormal gene is required to cause achondroplasia. The gene for achondroplasia is fully penetrant, meaning that everyone who possesses it has achondroplasia. No one with the gene escapes achondroplasia. However, there is some variation in expression of the gene, meaning that children with achondroplasia are not carbon copies of each other, although they may look alike to the untutored eye.
In only about an eighth of cases is the gene inherited from a parent who has achondroplasia. Rather, about seven-eighths of cases are due to a new mutation (a new change in the gene). This means that most cases of achondroplasia occur sporadically (out of the blue) and are the result of a new mutation in a sperm or ovum of one of the normal- appearing parents. The chance of a new mutation rises with the age of the father. As early as 1912 it was noted that sporadic (new) cases were more often last-born than first-born children. This fits with the fact that the chance of an achondroplastic birth has been shown to increase with paternal age (age of the father).
What if someone with achondroplasia has children?
Although most children with achondroplasia do not have an achondroplastic parent but have a new mutant gene for achondroplasia, they can still transmit the gene to their children, and the risk for passing that gene down to a child is 50% in each pregnancy.
What if two people with achondroplasia have children?
People with achondroplasia sometimes have children together. If so, each parent has a 50:50 chance of passing on the gene. Thus, with each conception, there is a 25% chance for an average-size child, a 50% chance for a child (like them) with achondroplasia and a 25% chance for a conception with two achondroplasia genes. The combined presence of two genes for achondroplasia (called homozygous achondroplasia) causes a grievous skeletal disorder that leads to early death from breathing failure due to constriction by a tiny chest cage and neurologic problems from hydrocephalus.
Lumbar stenosis can be caused by degenerative arthritis (the most common cause), tumor, infection, or metabolic disorders (Paget's disease of the bone). Symptoms include low back pain, weakness, pain, numbness, and loss of sensation in the legs. Other conditions may cause similar symptoms of lumbar stenosis, including diabetic neuropathy, claudication, and peripheral vascular disease. Diagnosis, is a medical history and imaging studies. Lumbar stenosis may be treated with medication or surgery.
Middle ear infection or inflammation (otitis media) is inflammation fo the middle ear. There are two types of otitis media, acute and chronic. Acute otitis media is generally short in duration, and chronic otitis media generally lasts several weeks. Seventy-five percent of children in the U.S. suffer from otitis media at some point. Treatment depends upon the type (chronic or acute).
Hydrocephalus is an abnormal buildup of cerebrospinal fluid (CSF) in the ventricles of the brain. The fluid is often under increased pressure and can compress and damage the brain. Symptoms of hydrocephalus vary with age, progression of the disease, and individual tolerance to the condition. Hydrocephalus is most often treated by surgery in which a shunt system is inserted.
Obesity is the state of being well above one's normal weight. A person has traditionally been
considered to be obese if they are more than 20 percent over their ideal weight.
That ideal weight must take into account the person's height, age, sex, and
build.
Genetic disease is a disorder or condition caused by abnormalities in a person's genome. Types of genetic inheritance include single inheritance (for example, cystic fibrosis, sickle cell anemia, Marfan syndrome, and hemochromatosis), multifactoral inheritance, chromosome abnormalities (for example, Turner syndrome, and Klinefelter syndrome), and mitochondrial inheritance (for example, epilepsy and dementia).
Kyphosis is outward curvature of the thoracic spine (upper back). Abnormal kyphosis results in the appearance of a hunchback, which is accompanied by back pain, stiffness, and muscle fatigue in the back. There are three types of abnormal kyphosis: postural, Scheuermann's, and congenital kyphosis. Postural kyphosis is caused by poor posture and a weakening of the back's muscles and ligaments. Scheuermann's kyphosis is caused by a structural deformity of the vertebrae. Congenital kyphosis is caused by an abnormal development of the vertebrae prior to birth. Treatment of kyphosis depends upon the type of kyphosis the patient has.
Birth defects have many causes and currently, are the leading cause of death for infants in the first year of life. Some of the causes of birth defects include genetic or chromosome problems. Exposure of the mother to rubella or German measles during pregnancy, or using drugs or alcohol during pregnancy. The treatment for birth defects depends upon the condition of the effected child.
Your health care provider may refer you to a genetic professional. Universities and medical centers also often have affiliated genetic professionals, or can provide referrals to a genetic professional or genetics clinic. Genetic counseling provides patients and family members the tools to make the right choice in regard to test for a disease or condition.