Prenatal Diagnosis of 4p and 4q Subtelomeric Microdeletion in De Novo Ring Chromosome 4

Ring chromosomes are unusual abnormalities that are observed in prenatal diagnosis. A 23-year-old patient (gravida 1, para 0) referred for amniocentesis due to abnormal maternal serum screening result in the 16th week of second pregnancy. Cytogenetic analysis of cultured amniyotic fluid cells revealed out ring chromosome 4. Both maternal and paternal karyotypes were normal. Terminal deletion was observed in both 4p and 4q arms of ring chromosome 4 by fluorescence in situ hybridization (FISH). However deletion was not observed in the WHS critical region of both normal and ring chromosome 4 by an additional FISH study. These results were confirmed by means of array-CGH showing terminal deletions on 4p16.3 (130 kb) and 4q35.2 (2.449 Mb). In the 21th week of pregnancy, no gross anomalia, except two weeks symmetric growth retardation, was present in the fetal ultrasonographic examination. According to our review of literature, this is the first prenatal case with 4p and 4q subtelomeric deletion of ring chromosome 4 without the involvement of WHS critical region. Our report describes the prenatal case with a ring chromosome 4 abnormality completely characterized by array-CGH which provided complementary data for genetic counseling of prenatal diagnosis.

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Prenatal diagnosis of mosaic ring chromosome 15 with abnormal maternal serum Down syndrome screening and Dandy-Walker malformation

Taiwanese Journal of Obstetrics and Gynecology ◽

10.1016/j.tjog.2012.01.022 ◽

2012 ◽

Vol 51 (1) ◽

pp. 109-111 ◽

Cited By ~ 5

Author(s):

Shun-Jen Tan ◽

Chi-Huang Chen ◽

Chih-Ping Chen ◽

Chun-Wen Chen ◽

Cheng-Yu Chen ◽

...

Keyword(s):

Down Syndrome ◽

Prenatal Diagnosis ◽

Ring Chromosome ◽

Maternal Serum ◽

Chromosome 15 ◽

Dandy Walker Malformation ◽

Walker Malformation ◽

Down Syndrome Screening

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Rapid and simple prenatal diagnosis of common chromosome disorders: advantages and disadvantages of the molecular methods FISH and QF-PCR

Reproduction ◽

10.1530/rep.0.1260279 ◽

2003 ◽

pp. 279-297 ◽

Cited By ~ 80

Author(s):

MA Hulten ◽

S Dhanjal ◽

B Pertl

Keyword(s):

Prenatal Diagnosis ◽

Sex Chromosome ◽

Chromosome Analysis ◽

Maternal Serum ◽

Molecular Techniques ◽

Maternal Serum Screening ◽

Advantages And Disadvantages ◽

Microscopy Analysis ◽

Chromosome Disorder

Molecular techniques have been developed for prenatal diagnosis of the most common chromosome disorders (trisomies 21, 13, 18 and sex chromosome aneuploidies) where results are available within a day or two. This involves fluorescence in situ hybridization (FISH) and microscopy analysis of fetal cells or quantitative fluorescence polymerase chain reaction (QF-PCR) on fetal DNA. Guidance is provided on the technological pitfalls in setting up and running these methods. Both methods are reliable, and the risk for misdiagnosis is low, although slightly higher for FISH. FISH is also more labour intensive than QF-PCR, the latter lending itself more easily to automation. These tests have been used as a preamble to full chromosome analysis by microscopy. However, there is a trend to apply the tests as 'stand-alone' tests for women who are at relatively low risk of having a baby with a chromosome disorder, in particular that associated with advanced age or results of maternal serum screening programmes. These women comprise the majority of those currently offered prenatal diagnosis with respect to fetal chromosome disorders and if introduced on a larger scale, the use of FISH and QF-PCR would lead to substantial economical savings. The implication, on the other hand, is that around one in 500 to one in 1000 cases with a mentally and/or physically disabling chromosome disorder would remain undiagnosed.

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A New Case of 13q12.2q13.1 Microdeletion Syndrome Contributes to Phenotype Delineation

Case Reports in Genetics ◽

10.1155/2014/470830 ◽

2014 ◽

Vol 2014 ◽

pp. 1-5

Author(s):

Giorgia Mandrile ◽

Eleonora Di Gregorio ◽

Alessandro Calcia ◽

Alessandro Brussino ◽

Enrico Grosso ◽

...

Keyword(s):

Clinical Features ◽

Critical Region ◽

Array Cgh ◽

De Novo ◽

Genetic Disorder ◽

Phenotypic Expression ◽

Microdeletion Syndrome ◽

Complex Rearrangement

A recently described genetic disorder has been associated with 13q12.3 microdeletion spanning three genes, namely,KATNAL1, LINC00426, andHMGB1. Here, we report a new case with similar clinical features that we have followed from birth to 5 years old. The child carried a complex rearrangement with a double translocation: 46,XX,t(7;13)(p15;q14),t(11;15)(q23;q22). Array-CGH identified ade novomicrodeletion at 13q12.2q13.1 spanning 3–3.4 Mb and overlapping 13q12.3 critical region. Clinical features resembling those reported in the literature confirm the existence of a distinct 13q12.3 microdeletion syndrome and provide further evidence that is useful to characterize its phenotypic expression during the 5 years of development.

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