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

Genetic Diagnostic Strategies and Counseling for Families Affected by Congenital Diaphragmatic Hernia

Congenital diaphragmatic hernia (CDH) is a relatively common and severe birth defect with variable clinical outcome and associated malformations in up to 60% of patients. Mortality and morbidity remain high despite advances in pre-, intra-, and postnatal management. We review the current literature and give an overview about the genetics of CDH to provide guidelines for clinicians with respect to genetic diagnostics and counseling for families. Until recently, the common practice was (molecular) karyotyping or chromosome microarray if the CDH diagnosis is made prenatally with a 10% diagnostic yield. Undiagnosed patients can be reflexed to trio exome/genome sequencing with an additional diagnostic yield of 10 to 20%. Even with a genetic diagnosis, there can be a range of clinical outcomes. All families with a child with CDH with or without additional malformations should be offered genetic counseling and testing in a family-based trio approach.

Prenatal profile of Pallister-Killian syndrome: Retrospective analysis of 114 pregnancies, literature review and approach to prenatal diagnosis

Pallister-Killian syndrome (PKS) is a tissue limited mosaic disorder, characterized by variable degrees of neurodevelopmental delay and intellectual disability, typical craniofacial findings, skin pigmentation anomalies and multiple congenital malformations. The wide phenotypic spectrum of PKS in conjunction with the mosaic distribution of the i(12p) makes PKS an underdiagnosed disorder. Recognition of prenatal findings that should raise a suspicion of PKS is complicated by the fragmentation of data currently available in the literature and challenges in diagnosing a mosaic diagnosis on prenatal testing. Ultrasound anomalies, especially congenital diaphragmatic hernia, congenital heart defects, and rhizomelic limb shortening, have been related to PKS, but they are singularly not specific and are not present in all affected fetuses. We have combined prenatal data from 86 previously published reports and from our cohort of 114 PKS probands (retrospectively reviewed). Summarizing this data we have defined a prenatal growth profile and identified markers of perinatal outcome which collectively provide guidelines for early recognition of the distinctive prenatal profile and consideration of a diagnosis of PKS as well as for management and genetic counseling.

Pallister-Killian syndrome: Review of fetal phenotype

Pallister-Killian syndrome is a multi-system sporadic disorder with developmental delay. It is a rare chromosomal abnormality involving supernumerary isochormosome 12p. The disorder exhibits tissue specific mosaicism. The first prenatal diagnosis of PKS was reported in 1985 after ultrasound detection of fetal anomalies. Since this observation, there have been about 62 reports of fetuses with PKS. In this review, we cover the prenatal aspects of PKS.

Targeted prenatal diagnosis of Pallister-Killian syndrome

OBJECTIVE

To present five new cases of prenatally diagnosed Pallister-Killian syndrome (PKS) and to propose an approach for a targeted diagnosis.

METHOD

We retrospectively analyzed ultrasound findings and cytogenetic results in PKS. We also searched through dysmorphology databases for features occurring in PKS that could potentially be seen in prenatal ultrasound examination.

RESULTS

On the basis of collected data, frequent and distinctive features in fetuses with PKS were established. The most appropriate material and method of testing were proposed. Rhizomelic limb shortening, diaphragmatic hernia, thickened nuchal fold, increased prenasal thickness, polydactyly and polyhydramnios were frequent and distinctive findings in fetuses with PKS. Amniocentesis was the most frequent prenatal procedure for material collection. Percentage of aneuploid cells was higher in amniotic fluid than in cord blood. Cytomolecular tests were useful as confirmation as well as preliminary tests. Cytogenetic identification of the isochromosome was done in all cases except one.

CONCLUSIONS

In case of ultrasound evaluation of features frequent and distinctive for PKS in second and third trimesters of pregnancy, targeted diagnosis should be considered. Amniotic fluid instead of cord blood collection is preferable. Communication with the laboratory is important because modification of routine procedures enhances a chance for correct diagnosis. © 2017 John Wiley & Sons, Ltd.

[Prenatal and clinicopathological study of 6 cases of Pallister-Killian syndrome and review]

OBJECTIVE

In multidisciplinary prenatal diagnosis centers, the search for a tetrasomy 12p mosaic is requested following the discovery of a diaphragmatic hernia in the antenatal period. Thus, the series of Pallister Killian syndromes (PKS: OMIM 601803) probably overestimate the prevalence of diaphragmatic hernia in this syndrome to the detriment of other morphological abnormalities.

METHODS

A multicenter retrospective study was conducted with search for assistance from members of the French society for Fetal Pathology. For each identified case, we collected all antenatal and postnatal data. Antenatal data were compared with data from the clinicopathological examination to assess the adequacy of sonographic signs of PKS. A review of the literature on antenatal morphological anomalies in case of PKS completed the study.

RESULTS

Ten cases were referred to us: 7 had cytogenetic confirmation and 6 had ultrasound screening. In the prenatal as well as post mortem period, the most common sign is facial dysmorphism (5 cases/6). A malformation of limbs is reported in half of the cases (3 out of 6). Ultrasound examination detected craniofacial dysmorphism in 5 cases out of 6. We found 1 case of left diaphragmatic hernia. Our results are in agreement with the malformation spectrum described in the literature.

CONCLUSION

Some malformation associations could evoke a SPK without classical diaphragmatic hernia.