Biomedical subjects

K Amiri

Publications and source records attributed to K Amiri.

4 recordsLinked to original sources

PubMed1992

Girls with fragile X syndrome: physical and neurocognitive status and outcome.

The fragile X syndrome, a common X-linked form of mental retardation and autism, affects females as well as males. Previous work has shown that approximately 35% of heterozygotes (women who carry the fragile X gene) demonstrate cognitive impairment. Thirty-two girls, 18 years or younger, who demonstrate the fragile X chromosome were evaluated and compared with 19 sisters who do not demonstrate the fragile X chromosome. Evaluations included a physical examination, behavioral assessment, and intelligence testing. Significant differences (in intellectual, behavioral, and physical features) were seen between the two groups. Twenty-five percent of fragile X-positive girls had an IQ in the mentally retarded range (IQ less than 70) and 28% had an IQ in the borderline range (70 to 84). Prominent ears, shyness, and poor eye contact were significant findings in fragile X-positive girls compared with fragile X-negative girls. Thirty-one percent of the fragile X-positive girls had significant attentional difficulties and most of these girls were successfully treated with stimulant medication. The majority of fragile X-positive girls in this study demonstrated significant behavioral and developmental problems which required identification and appropriate treatment. Pediatricians and health care providers should be aware of the frequency and manner with which fragile X affects females in order to initiate cytogenetic studies and treatment when indicated.

Adolescent↗

PubMedDate not supplied

Heterozygous fragile X female: historical, physical, cognitive, and cytogenetic features.

Historical, physical, cognitive, and cytogenetic data were documented in 105 heterozygous fragile X [fra(X)] females and 90 controls in a prospective fashion. For comparisons, we divided heterozygotes and controls into those with cognitive impairment (IQ less than 85) and normal IQ (IQ greater than or equal to 85). The only finding that was significantly more frequent in impaired heterozygotes compared with impaired controls chi 2 analysis was shyness. Features that were more frequent in normal IQ heterozygotes compared with normal controls were voluntary thumb dislocation and hyperextensible metacarpal-phalangeal (MP) joints. Comparisons among heterozygotes demonstrated more math problems, hand biting, strabismus, high-arched palate, hyperextensible finger joints, and flat feet in impaired heterozygotes than in normal heterozygotes. Premature menopause was present in 8 of 61 normal heterozygotes and in none of the impaired heterozygotes. A multiple regression analysis demonstrated a significant inverse correlation between the percent fragility and IQ for the heterozygotes as a group. However, no correlation existed between IQ and fragility when the percent fragility was 2% or greater. However, a higher percentage of fragility was positively correlated with the total number of physical findings present.

Adolescent↗

PubMedDate not supplied

Fragile X checklist.

A 13-item checklist that combines physical and behavioral traits typical of fragile X [fra(X)] syndrome was evaluated prospectively in the screening of 107 males with mental retardation or severe learning disabilities. The checklist was completed before we obtained cytogenetic results. Fifteen males were fra(X)-positive and the manifestations that differentiated fra(X)-positive and fra(X)-negative patients included perseverative speech, large or prominent ears, large testicles, and tactile defensiveness. The combination of physical and behavioral traits is helpful in suggesting the diagnosis and identifying high-risk patients. A total score of 16 or higher had a significant yield of fra(X)-positive patients (greater than or equal to 45%).

Age Factors↗

PubMedDate not supplied

Mental impairment in cytogenetically positive fragile X females.

Prenatal diagnosis is now available to fragile X (fra[X]) syndrome families and has proven reliable when testing male fetuses. It has been reported that approximately one-third of heterozygous fra(X) females demonstrate mental impairment. Based on this, families usually continue pregnancies involving a female fetus. The purpose of this study is to investigate whether a 35% risk for mental impairment is appropriate when counseling heterozygous women carrying fra(X)-positive female fetuses. Forty-three cytogenetically positive (greater than or equal to 2%) daughters of known fra(X) carrier women were ascertained postnatally in an unbiased fashion. Their mother's carrier status was determined on the basis of at least one son with Martin-Bell syndrome. In addition to peripheral blood cytogenetic studies, all daughters had cognitive testing to determine full-scale IQ. In this study, 55.8% (24/43) were mentally impaired (IQ less than 85) compared with the expected 35%. Of these, 42% were mentally retarded (IQ less than 70). Although we do not know the correlation between percent fragility by peripheral blood compared with the percent fragility by amniocentesis or CVS, we assume that they are relatively comparable such that a female who is positive with greater than or equal to 2% fragility would probably be positive by all methods. This report suggests that the penetrance of mental impairment in females with a percent fragility of greater than or equal to 2% may be as high as 55%. Further studies are necessary to clarify this issue so that accurate information can be given in genetic counseling.

Adolescent↗