Congenital malformations - Edocr

CHAPTER 27 SEPTAL DEFECTS 177
TABLE 27–1 Syndromes Commonly Associated with Cardiac Septal Defects (Continued)
Type of Cardiac Other Associated
Syndrome Defect Findings Etiology
Teratogenic Syndromes:
Fetal alcohol VSD, ASD Microcephaly; small size; Prenatal alcohol
syndrome short palpebral fissures; exposure
simple philtrum; thin
upper lip
Maternal diabetic VSD Other cardiac defects such Abnormal maternal
embryopathy as tetralogy of Fallot glucose metabolism
and truncus arteriosus;
neural tube defects;
holoprosencephaly;
caudal regression
syndrome; focal femoral
hypoplasia
Maternal PKU VSD Microcephaly; intrauterine Intrauterine exposure
syndrome growth retardation; to high phenylalanine
dysmorphic facies
levels
resembling those seen
in fetal alcohol syndrome
Valproic acid ASD,VSD Dysmorphic facies; joint Prenatal exposure to
embryopathy contractures; spina bifida valproic acid
ASD is inherited in an autosomal dominant pattern.
Mutations in NKX2.5 have been identified
in families in which ASD is associated with conduction
abnormalities, specifically progressive
atrioventricular block, as well as in a small
percentage of sporadic ASD patients. 1,2 Mutations
in the GATA4 zinc finger transcription factor gene
have been identified in families with autosomal
dominant ASDs and normal conduction. 3 Some
patients with the latter defects have had additional
cardiac lesions, particularly valvar pulmonic
stenosis.
TREATMENT AND PROGNOSIS
Most ASDs remain asymptomatic, even when
untreated and do not pose a risk for bacterial
endocarditis. Spontaneous closure often occurs
in the first year of life. Defects associated with
a significant left to right shunt may produce pulmonary
obstructive vascular disease in 5–10%
of cases. Large atrial communications increase
the risk of paradoxical emboli. For large defects,
surgical closure is usually the accepted method
of treatment, regardless of the presence or absence
of symptoms. In some cases, catheter-based
repair may be possible.
GENETIC COUNSELING
A complete family history should be obtained
prior to providing genetic counseling to the parents
of an infant with an ASD. If there are any
other family members with structural cardiac defects,
conduction disorders, or arrhythmias, caution
should be exercised before assuming that
the patient has an isolated, multifactorial defect.
Such a history may suggest autosomal dominant
inheritance, particularly if a parent is affected. In
families with autosomal dominant inheritance of
ASD, the recurrence risk in future pregnancies is
50%. In the case of isolated sporadic cases with
no other family history, the recurrence risk for
future siblings is approximately 3%.