We would like to present a rare case of alobar holoprosencephaly (HPE) in a fetus diagnosed by routine sonography in the second trimester. Structural sonography demonstrated multiple facial anomalies including absent nasal bone, flat facial profile, hypotelorism, fusion of the orbits and proboscis. After counseling, termination of pregnancy was performed by vaginally administered misoprostol. K...

OBJECTIVE To present prenatal diagnosis and molecular cytogenetic characterization of a derivative chromosome der(18;18)(q10;q10)del(18)(q11.1q12.1)del(18)(q22.1q22.3). MATERIALS, METHODS, AND RESULTS A 32-year-old woman was referred for genetic counseling of prenatally detected isochromosome 18q [i(18q)]. She had undergone amniocentesis at 19 gestational weeks because of a trisomy 18 risk of...

The common causes of 18p deletion syndrome are spontaneous errors in the chromosomal structure in the early stages of human embryonic development. In this study, a 29-year-old girl was introduced with the features of deletion of chromosome 18. In addition, GTG banding karyotype revealed that this case had a deletion involving the short arm of chromosome 18. In comparison with the usual phenotyp...

Thus far, the phenotype of tetrasomy 18p has been primarily delineated by published case series and reports. Findings reported in more than 25% of these cases include neonatal feeding problems, growth retardation, microcephaly, strabismus, muscle tone abnormalities, scoliosis/kyphosis, and variants on brain MRI. Developmental delays and cognitive impairment are universally present. The purpose ...

IntroductIon The tetrasomy 18p (OMIM 614290) is a very rare chromosomal abnormality, with a prevalence of 1/140,000–180,000 live births.[1] Although it has been known in some countries, it has been seldom reported in China. Especially, mosaicism for tetrasomy 18p is even rare. Because of a very limited number of cases, the phenotypic spectrum of mosaic tetrasomy 18p, the complications, and prog...

Tetrasomy 18p, one of the most commonly observed isochromosomes, consists of two copies of the p arms on chromosome 18[i(18p)]. It is known as a de novo occurrence of non-disjunction or centromeric mis-division during meiosis II in the vast majority of cases. It has a prevalence of 1/140,000-180,000 live births and affects both genders equally. A 28-year-old woman was referred at 33+2 weeks ges...

Facioscapulohumeral muscular dystrophy (FSHD) is most often associated with variegated expression in somatic cells of the normally repressed DUX4 gene within the D4Z4-repeat array. The most common form, FSHD1, is caused by a D4Z4-repeat array contraction to a size of 1-10 units (normal range 10-100 units). The less common form, FSHD2, is characterized by D4Z4 CpG hypomethylation and is most oft...

Supernumerary marker chromosomes (SMCs) are rare chromosomal abnormalities resulting in partial trisomy of specific genomic regions with characteristic phenotypic effects. Twenty six cases with autosomal SMCs are reported. Four were identified prenatally and 22 postnatally in children, aged from 8 days to 15 years, who were referred for genetic evaluation because of various congenital anomalies...

BACKGROUND Pallister-Killian syndrome (PKS) is a prototypic mosaic aneuploidy syndrome caused by mosaic supernumerary marker isochromosome 12p. Cells possessing the isochromosome 12p rapidly diminish after birth in the peripheral blood, often necessitating a skin biopsy for diagnosis. Therefore, a genomic testing that is capable of detecting low percent mosaic isochromosome 12p is preferred for...

A three generation pedigree is described in which there are two carriers of translocation t(7;18). Two members of the family have trisomy 18p and a stillborn child had monosomy 18p and holoprosencephaly. Another stillborn child probably had holoprosencephaly; the karyotype was not analysed. Based on this observation, the occasional occurrence of holoprosencephaly in monosomy 18p (10% of previou...