Clinical and radiological findings in Pallister-Killian syndrome.

Genetics Service, Department of Paediatric Medicine, KK Hospital, Singapore.
European journal of medical genetics (Impact Factor: 1.57). 02/2012; 55(3):167-72. DOI: 10.1016/j.ejmg.2012.01.019
Source: PubMed

ABSTRACT Pallister-Killian syndrome (PKS) is a potentially lethal disorder with facial dysmorphism, pigmentary skin anomalies, developmental delay and major visceral anomalies, such as diaphragmatic hernia, anorectal malformation, and congenital heart disease. PKS is causally associated with mosaic tetrasomy of chromosome 12p. A routine chromosome analysis in peripheral lymphocytes usually fails to detect the mosaic state. A prompt diagnosis rests on clinical awareness and a subsequent chromosome or molecular analysis in fibroblasts, buccal mucosal cells, or bone marrow cells. We report here on three infants with PKS. One infant had aortic dilatation, a previously unreported association in PKS. More importantly, all infants showed a recognizable, though mild, pattern of skeletal changes mainly affecting axial bones, including delayed ossification of the vertebral bodies and pubic bones, flared anterior ribs, and broad metaphyses of the long bones, particularly of the femora. These skeletal changes should be considered as a useful diagnostic sign in PKS. Awareness of the axial skeletal alterations can be helpful in prompting clinicians to search for mosaic tetrasomy 12p and perform chromosomal analysis in appropriate tissue types.

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    ABSTRACT: Patient: Male, 0 Final Diagnosis: Pallister-Killian syndrome Symptoms: 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 nipples Medication: - Clinical Procedure: - Specialty: Pediatrics and Neonatology. Congenital defects/diseases. 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. 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. The occurrence of PKS is sporadic in nature, but prenatal diagnosis is possible.
    The American journal of case reports. 01/2014; 15:194-8.
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    ABSTRACT: BACKGROUND: Although there is increasing recognition of the role of somatic mutations in genetic disorders, the prevalence of somatic mutations in neurodevelopmental disease and the optimal techniques to detect somatic mosaicism have not been systematically evaluated. METHODS: Using a customized panel of known and candidate genes associated with brain malformations, we applied targeted high-coverage sequencing (depth, ≥200×) to leukocyte-derived DNA samples from 158 persons with brain malformations, including the double-cortex syndrome (subcortical band heterotopia, 30 persons), polymicrogyria with megalencephaly (20), periventricular nodular heterotopia (61), and pachygyria (47). We validated candidate mutations with the use of Sanger sequencing and, for variants present at unequal read depths, subcloning followed by colony sequencing. RESULTS: Validated, causal mutations were found in 27 persons (17%; range, 10 to 30% for each phenotype). Mutations were somatic in 8 of the 27 (30%), predominantly in persons with the double-cortex syndrome (in whom we found mutations in DCX and LIS1), persons with periventricular nodular heterotopia (FLNA), and persons with pachygyria (TUBB2B). Of the somatic mutations we detected, 5 (63%) were undetectable with the use of traditional Sanger sequencing but were validated through subcloning and subsequent sequencing of the subcloned DNA. We found potentially causal mutations in the candidate genes DYNC1H1, KIF5C, and other kinesin genes in persons with pachygyria. CONCLUSIONS: Targeted sequencing was found to be useful for detecting somatic mutations in patients with brain malformations. High-coverage sequencing panels provide an important complement to whole-exome and whole-genome sequencing in the evaluation of somatic mutations in neuropsychiatric disease. (Funded by the National Institute of Neurological Disorders and Stroke and others.).
    New England Journal of Medicine 08/2014; 371(8):733-43. · 54.42 Impact Factor
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    ABSTRACT: Pallister Killian syndrome (OMIM: # 601803) is a rare multisystem disorder typically caused by tissue limited mosaic tetrasomy of chromosome 12p (isochromosome 12p). The clinical manifestations of Pallister Killian syndrome are variable with the most common findings including craniofacial dysmorphia, hypotonia, cognitive impairment, hearing loss, skin pigmentary differences and epilepsy. Isochromosome 12p is identified primarily in skin fibroblast cultures and in chorionic villus and amniotic fluid cell samples and may be identified in blood lymphocytes during the neonatal and early childhood period. We performed genomic expression profiling correlated with interphase fluorescent in situ hybridization and single nucleotide polymorphism array quantification of degree of mosaicism in fibroblasts from 17 Caucasian probands with Pallister Killian syndrome and 9 healthy age, gender and ethnicity matched controls. We identified a characteristic profile of 354 (180 up- and 174 down-regulated) differentially expressed genes in Pallister Killian syndrome probands and supportive evidence for a Pallister Killian syndrome critical region on 12p13.31. The differentially expressed genes were enriched for developmentally important genes such as homeobox genes. Among the differentially expressed genes, we identified several genes whose misexpression may be associated with the clinical phenotype of Pallister Killian syndrome such as downregulation of ZFPM2, GATA6 and SOX9, and overexpression of IGFBP2.
    PLoS ONE 01/2014; 9(10):e108853. · 3.53 Impact Factor