1.Holoprosencephaly: an antenatally-diagnosed case series and subject review.
Alvin S T LIM ; Tse Hui LIM ; Su Keyau KEE ; Patrick CHIA ; Subramaniam RAMAN ; Elizabeth L P EU ; Jessie Y C LIM ; Sim Leng TIEN
Annals of the Academy of Medicine, Singapore 2008;37(7):594-597
<p>INTRODUCTIONHoloprosencephaly (HPE) is an uncommon congenital failure of forebrain development. Although the aetiology is heterogeneous, chromosomal abnormalities or a monogenic defect are the major causes, accounting for about 40% to 50% of HPE cases. At least 7 genes have been positively implicated, including SHH, ZIC2, SIX3, TGIF, PTCH1, GLI2, and TDGF1.p><p>CLINICAL PICTURETwelve antenatally- and 1 postnatally-diagnosed cases are presented in this study. These comprised 6 amniotic fluid, 3 chorionic villus, 2 fetal blood, 1 peripheral blood, and 1 product of conception.p><p>OUTCOMEThe total chromosome abnormality rate was 92.3%, comprising predominantly trisomy 13 (66.7%). There was 1 case of trisomy 18, and 3 cases of structural abnormalities, including del13q, del18p, and add4q.p><p>CONCLUSIONDespite the poor outcome of an antenatally-diagnosed HPE and the likely decision by parents to opt for a termination of pregnancy, karyotyping and/or genetic studies should be performed to determine if a specific familial genetic or chromosomal abnormality is the cause. At the very least, a detailed chromosome analysis should be carried out on the affected individual. If the result of high resolution karyotyping is normal, Fluorescence in situ hybridisation (FISH) and/or syndrome-specific testing or isolated holoprosencephaly genetic testing may be performed. This information can be useful in making a prognosis and predicting the risk of recurrence.p>
Adult
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Chromosome Aberrations
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Female
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Holoprosencephaly
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diagnosis
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genetics
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Humans
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Karyotyping
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Pregnancy
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Prenatal Diagnosis
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Trisomy