Angelman syndrome

WAIKOLOA VILLAGE, HAWAII -- Minor congenital anomalies can be an important tip-off that mental retardation or another neurologic disorder in childhood is caused by a congenital syndrome rather than a problem that occurred during labor and delivery.

It's therefore critical that a child be examined by a clinical geneticist or dysmorphologist whenever malpractice litigation cites fetal distress or perinatal asphyxia as the cause of a childhood neurologic disorder, Dr. Aubrey Milunsky advised at a conference on obstetrics, gynecology, perinatal medicine, neonatology, and the law.

Minor malformations may not be obvious, and a primary care physician may not recognize them, said Dr. Milunsky, professor of human genetics, pediatrics, ob.gyn., and pathology at Boston University.

Examples of minor malformations include the absence of a hair whorl, extra nipples, frontal bossing, iris freckles, tapered fingers, and a cleft uvula. "The list is very long," he noted at the meeting sponsored by the university.

More than 2,000 congenital syndromes have been classified so far. "You don't have to know all of them," he said. But a clinical geneticist will be able to detect the most subtle of minor malformations, input them into a computer, and then search sever databases to come up with a differential diagnosis.

About 10% of children with two minor malformations have a major abnormality, such as a cardiac malformation or a neurologic disorder, such as mental retardation, developmental delay seizures, spasticity, and psychosis. About 20% of children with three or more minor malformations have a major abnormality, he said.

The presence of minor malformations suggests that associated neurologic problems originated early in gestation, particularly at 6- to 12-weeks' gestation, rather than during labor and delivery.

"It's not surprising that abnormalities of the skin, hair, and nails may reflect a brain abnormality, given their shared embryological ectodermal origins," Dr. Milunsky commented.

The cause of these syndromes may be inherited genes; a new gene mutation; or environmental factors, such as maternal exposure to an infection, drug, toxin, radiation, or heat.

Examples of congenital syndromes with neurologic dysfunction that could erroneously be attributed to perinatal asphyxia include fragile X syndrome, Prader-Willi syndrome, and Angelman syndrome, which resembles cerebral palsy.

Babies with these syndromes may very well have had problems during labor and delivery, "but it's axiomatic that bad babies, with congenital defects, do badly in labor. The mere fact that things are difficult in labor does not mean that the labor was the cause of the problem," Dr. Milunsky said.

During the discussion period, Dr. Maurice L. Druzin noted that babies with chromosomal and/or structural abnormalities often have abnormal antepartum and intrapartum fetal heart rate tracings. Normal fetal heart rate tracings in labor usually predict infants will be normal.

But if infants have normal fetal heart rate tracings during delivery and then suddenly decompensate afterward, it's critical to quickly think about a congenital anomaly, such as a diaphragmatic hernia or cardiac abnormalities, or group B strep sepsis, said Dr. Druzin, chief of maternal fetal medicine at Stanford (Calif.) University.

"Look for these causes so that the words 'perinatal asphyxia' do not appear on the chart. Once they appear, they're set in stone and you have to fight to disavow that diagnosis," he warned.

Blood Test Finds Velocardiofacial Syndrome

WAIKOLOA VILLAGE, HAWAII - A simple blood test can now identify families with velocardiofacial syndrome, a chromosome abnormality that occurs in 1 in every 2,000 live born infants.

The syndrome, caused by a sporadic or autosomally inherited microdeletion on chromosome 22q, can result in a broad spectrum of abnormalities, Dr. Aubrey Milunsky said at a conference on obstetrics, gynecology, perinatal medicine, neonatology, and the law.

These include subtle dysmorphic features of a long and narrow face, flat cheeks, and minor ear anomalies. Other conditions associated with the syndrome include cleft palate, speech defects, developmental delay, mental retardation, congenital cardiac defects, and psychiatric disorders.

Women with a cluster of these conditions in their family history warrant prenatal genetic counseling for possible testing using a technique called fluorescence in situ hybridization (FISH), said Dr. Milunsky, professor of human genetics, pediatrics, ob.gyn., and pathology at Boston University.

In children, congenital heart defects and learning disabilities are the most common manifestations that should prompt a referral to a geneticist, he added at the meeting, sponsored by the university.

Of note is that the psychiatric conditions associated with velocardiofacial syndrome change with age. Children with the syndrome who are 5-10 years old tend to have attention-deficit hyperactivity disorder. Those 11-18 years old tend to have bipolar disorder or obsessive-compulsive disorder. Adults tend to have bipolar disorder, psychosis, or schizoaffective disorder, he said.

Barbara Baker

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