Diagnosis Of Pallister-Killian Syndrome Research Articles

Hypotonic infant with Pallister–Killian syndrome diagnosed by cytogenetic microarray, without pigmentary skin changes and malformations

Pallister-Killian syndrome (PKS) is a rare genetic developmental disorder characterized, by intellectual disability, seizures, streaks of hypo- or hyperpigmentation and characteristic dysmorphic features. PKS is characterized by the presence of cytogenetic abnormality in form of a supernumerary isochromosome 12p, in a tissue limited mosaicism. The isochromosome 12p is usually not detected in karyotype done from peripheral blood. Presence of patchy pigmentary skin lesions suggest the possibility of mosaicism and karyotype from skin is done which clinches the diagnosis. We describe an infant with severe hypotonia in whom trisomy 12p was detected bychromosomal microarray performed on peripheral blood. The karyotype from blood was normal and combining this information with three copies of 12p in microarray suggests the possibility of tetrasomy12p in mosaic form. The infant did not have any skin patchy pigmentary changes and malformations and hence, the diagnosis of PKS was not clinically suspected. Cytogenetic microarray is the first test for evaluation of cases with developmental delay and intellectual disability, PKS diagnosis may come as a surprise in unsuspected caseswithout characteristic skin pigmentary abnormality and malformations.

Prenatal diagnosis of Pallister-Killian syndrome using cord blood samples

BackgroundPallister-Killian syndrome (PKS) (OMIM:#601803) is a rare sporadic genetic disorder characterized by multi-malformations which is caused by the presence of the extra isochromosome 12p. PKS is featured by the tissue-limited mosaicism of the isochromosome 12p [i(12p)]. There were a wide spectrum of prenatal ultrasound findings of PKS, which made it difficult to be found in first or second trimester. Polyhydramnios, diaphragmatic hernia, and rhizomelic limb shortening were the most common prenatal ultrasound abnormalities in PKS. This study retrospectively analyzed the ultrasound findings and molecular cytogenetic results of four PKS fetuses diagnosed by using cord blood samples.ResultsThe ultrasound anomalies of four PKS fetuses are described as follows: fetal macrosomia, cerebral ventriculomegaly, increased NT thickness, rhizomelic limbs shortening, polyhydramnios. Biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), femur length (FL) measurements were above the mean in three fetuses,while one fetus showed rhizomelic limbs shortening. Combined with this study and previous literature, polyhydramnios was the most frequent anomaly observed in prenatal ultrasound examination of PKS, which accounted for 48% (94/194). Fetal macrosomia was present in 15% (29/194), cerebral ventriculomegaly in 13% (25/194), thickened nuchal fold in 9% (18/194), rhizomelic limbs shortening in 26% (51/194). I(12p) was found in the karyotype analysis of cultured cord blood lymphocytes and the mosaic ratios ranged from 2 to 5%. Single nucleotide polymorphisms array (SNP-array) results suggested that the whole short arm of chromosome 12 was duplicated with 2~3 copies. Fluorescence in situ hybridization (FISH) was performed to confirm the results of karyotype and SNP-array.ConclusionsIn case non-specific indicators such as fetal macrosomia, polyhydramnios and rhizomelic limbs shortening are observed meanwhile in prenatal ultrasound, targeted detection of PKS should be considered. In the prenatal diagnosis of PKS, the combination of SNP-array and FISH with conventional karyotype are the key to seek i(12p) and for precise diagnosis.

Pallister-Killian Syndrome: Undetected by Percutaneous Umbilical Blood Karyotyping and Neonatal Blood Microarray Comparative Genomic Hybridization

Pallister-Killian Syndrome (PKS) is a rare sporadic genetic disorder and tissue-limited characteristics of i(12p) mosaicism. We report a boy who is diagnosed with PKS until the age of 2 years and 3 months. Amniocentesis at 18 weeks of gestation due to advanced maternal age revealed a mosaic supernumerary marker chromosome (47,XY,+mar[30]/46,XY[28]) which was suspected to be an isochromosome 21q. At 21 weeks of gestation, subsequent fetal blood sampling done in another clinic disclosed a normal male karyotype (46,XY). Therefore, the mother chose to continue pregnancy. A conventional chromosome analysis complements the Fluorescence In-Situ Hybridization (FISH) and array Comparative Genomic Hybridization (aCGH) were done from patient’s skin fibroblast culture.The karyotype was confirmed to be mos47,XY,+mar.ish i(12p)[110]/46,XY[11], and array CGH revealed a fourfold increment in 12p. Amniocentesis and conventional chromosomal analysis complements the FISH and array CGH is the optimal method in prenatal diagnosis of PKS. However fetal blood sampling chromosome analysis and peripheral blood array CGH are not recommended because of tissue-limited mosaicism of i(12p) is the characteristic cytogenetic feature of PKS and the extra-chromosome can rarely be identified in blood lymphocyte either prenatally or postnatally.

Prenatal diagnosis of Pallister Killian Syndrome in a fetus with congenital diaphragmatic hernia, short limbs, and increased nuchal translucency

a Department of Obstetrics and Gynecology, Abant _ Izzet Baysal University Medical Faculty, Bolu, Turkey b Department of Medical Genetics, Suleymaniye Maternity Hospital for Research and Training, Istanbul, Turkey c Department of Medical Genetics, Abant _ Izzet Baysal University Medical Faculty, Bolu, Turkey d Department of Perinatology, Suleymaniye Maternity Hospital for Research and Training, Istanbul, Turkey

Pallister-Killian syndrome.

Patient: Male, 0Final Diagnosis: Pallister-Killian syndromeSymptoms: Decidious tooth • flattened nasal bridge • frontal bossing • grooved palate • low-set ears • mid-facial hypoplasia • nuchal fold thickening • right inquinal testis • shortened upper extremities • undescended left intraabdominal testis • widely spaced nipplesMedication: —Clinical Procedure: —Specialty: Pediatrics and NeonatologyObjective:Congenital defects/diseasesBackground:Pallister-Killian syndrome (PKS) is a rare, sporadic, polydysmorphic condition that often has highly distinctive features. The clinical features are highly variable, ranging from mild to severe intellectual disability and birth defects. We here report the first case of PKS diagnosed at our institution in a patient in the second trimester of pregnancy.Case Report:A pregnant 43-year-old woman presented for genetic counseling secondary to advanced maternal age and an increased risk for Down syndrome. Ultrasound showed increased fetal nuchal fold thickness, short limbs, polyhydramnios, and a small stomach. The ultrasound evaluation was compromised due to the patient’s body habitus. The patient subsequently underwent amniocentesis and the karyotype revealed the presence of an isochromosome in the short arm of chromosome 12 consistent with the diagnosis of Pallister-Killian syndrome. Postnatally, the infant showed frontal bossing, a flattened nasal bridge, mid-facial hypoplasia, low-set ears, a right upper deciduous tooth, grooved palate, nuchal fold thickening, widely spaced nipples, left ulnar polydactyly, simian creases, flexion contractures of the right middle finger, shortened upper extremities, undescended left intraabdominal testis, and right inguinal testis.Conclusions:The occurrence of PKS is sporadic in nature, but prenatal diagnosis is possible.

Array CGH on unstimulated blood does not detect all cases of Pallister–Killian syndrome: A skin biopsy should remain the diagnostic gold standard

A child whose features are consistent with Pallister-Killian syndrome (PKS) did not have detectable tetrasomy 12p due to an additional isochromosome 12p in an unstimulated blood specimen by interphase FISH or array CGH analysis. The diagnosis of PKS was made through these methods solely in a skin biopsy specimen. To determine the sensitivity of our array CGH platform to tetrasomy 12p mosaicism, dilutions of DNA from both the child's skin fibroblasts and a PKS cell line were analyzed. Tetrasomy 12p at 10% mosaicism was identifiable but 5% was below the limit of detection. This result suggests through extrapolation that the tetrasomy 12p is present in <10% of cells in our patient's blood, confirming the tissue-limited mosaicism of PKS. Multiple recent studies show that array CGH provides greater sensitivity than chromosome analysis to detect mosaic abnormalities including that of tetrasomy 12p in blood specimens. However, our case demonstrates that the biology of PKS precludes the exclusive use of array CGH on blood for diagnosis. A tissue sample should continue to be the diagnostic gold standard for PKS.

Contribution of 3D ultrasound and fetal face studies to the prenatal diagnosis of Pallister-Killian syndrome

Contribution of 3D ultrasound and fetal face studies to the prenatal diagnosis of Pallister-Killian syndrome

Pallister–Killian Syndrome: Multiband FISH of Tetrasomy 12p

Two patients with mosaicism for tetrasomy 12p are described. One was diagnosed at the age of 14 years with severe mental retardation and other dysmorphologic findings and abnormal skin pigmentation. Chromosome analysis of a blood sample showed a normal female karyotype. A skin biopsy specimen showed mosaicism for a marker chromosome. The other patient was diagnosed prenatally, from a chorionic villus sample, but only in the direct preparation. Mosaicism for a marker chromosome was demonstrated. The ultrasound examination revealed no abnormalities. Multicolor and multiband fluorescence in situ hybridization analyses showed that the marker chromosome was derived from chromosome 12p, which confirmed the diagnosis of Pallister-Killian syndrome in both patients. To our knowledge, this is the first report of the use of these fluorescence in situ hybridization techniques in Pallister-Killian syndrome whereby the nature of the marker chromosome could be confirmed to be derived from chromosome 12p.

Pallister-Killian syndrome: report of one case.

Pallister-Killian Syndrome (PKS) is a rare sporadic congenital anomaly disorder, characterized by multiple congenital anomalies, especially craniofacial dysmorphism. It is also associated with mental retardation, seizure, skin pigmentation, and visceral malformations such as congenital diaphragmatic hernia, congenital heart defect, anorectal anomalies, and genital malformation. This syndrome usually presents with tissue-limited mosaicism of supernumerary 12p isochromosome i (12p). Moreover, diagnosis of Pallister-Killian Syndrome (PKS) is difficult because the ratio of abnormal to normal karyotyping is much lower in peripheral lymphocytes than in skin fibroblasts. We report the first case in Taiwan, who has tetrasomy 12p mosaic in peripheral lymphocytes.

Failure of PHA-stimulated i(12p) lymphocytes to divide in Pallister-Killian syndrome.

The diagnosis of Pallister-Killian syndrome (PKS) is confirmed by tissue-specific mosaicism of i(12p). The isochromosome is found in skin fibroblasts and bone marrow, but rarely in peripheral lymphocytes. The nature of the isochromosome loss was evaluated using 2 techniques: micronucleus formation for anaphase lag and in situ DNA hybridization for mosaicism in interphase cells. Cells from serial cultured fibroblasts, peripheral blood lymphocytes, and bone marrow from 4 PKS patients were used for the above analysis. Micronucleus formation was similar for PKS and normal diploid cultures, ruling out loss of i(12p) by anaphase lag as the major mechanism of in vitro mosaicism. In situ hybridization using an alpha satellite DNA probe for chromosome 12 was used to examine the presence of the i(12p) in interphase fibroblasts from 1 patient and lymphocytes from 2 patients (age 8 weeks and 1 day). The i(12p) was present in a significantly higher proportion of interphase nuclei in peripheral lymphocytes than in metaphase, suggesting the initial loss of the isochromosome is exaggerated in metaphase by selective division in vitro. In situ hybridization of peripheral lymphocyte interphase cells with chromosome 12 specific probes may be a useful supplemental procedure for the diagnosis of PKS, at least in the newborn infant.