Frontiers in Cell and Developmental Biology (Jan 2023)

PHIP-associated Chung-Jansen syndrome: Report of 23 new individuals

  • Antje Kampmeier,
  • Elsa Leitão,
  • Ilaria Parenti,
  • Jasmin Beygo,
  • Christel Depienne,
  • Nuria C Bramswig,
  • Tzung-Chien Hsieh,
  • Alexandra Afenjar,
  • Stefanie Beck-Wödl,
  • Ute Grasshoff,
  • Tobias B Haack,
  • Emilia K Bijlsma,
  • Claudia Ruivenkamp,
  • Eva Lausberg,
  • Miriam Elbracht,
  • Maria K Haanpää,
  • Maria K Haanpää,
  • Hannele Koillinen,
  • Hannele Koillinen,
  • Uwe Heinrich,
  • Imma Rost,
  • Rami Abou Jamra,
  • Denny Popp,
  • Margarete Koch-Hogrebe,
  • Kevin Rostasy,
  • Vanesa López-González,
  • Vanesa López-González,
  • María José Sanchez-Soler,
  • Catarina Macedo,
  • Ariane Schmetz,
  • Carmen Steinborn,
  • Sabine Weidensee,
  • Hellen Lesmann,
  • Felix Marbach,
  • Pilar Caro,
  • Christian P. Schaaf,
  • Peter Krawitz,
  • Dagmar Wieczorek,
  • Dagmar Wieczorek,
  • Frank J Kaiser,
  • Frank J Kaiser,
  • Alma Kuechler,
  • Alma Kuechler

DOI
https://doi.org/10.3389/fcell.2022.1020609
Journal volume & issue
Vol. 10

Abstract

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In 2016 and 2018, Chung, Jansen and others described a new syndrome caused by haploinsufficiency of PHIP (pleckstrin homology domain interacting protein, OMIM *612,870) and mainly characterized by developmental delay (DD), learning difficulties/intellectual disability (ID), behavioral abnormalities, facial dysmorphism and obesity (CHUJANS, OMIM #617991). So far, PHIP alterations appear to be a rare cause of DD/ID. “Omics” technologies such as exome sequencing or array analyses have led to the identification of distinct types of alterations of PHIP, including, truncating variants, missense substitutions, splice variants and large deletions encompassing portions of the gene or the entire gene as well as adjacent genomic regions. We collected clinical and genetic data of 23 individuals with PHIP-associated Chung-Jansen syndrome (CHUJANS) from all over Europe. Follow-up investigations (e.g. Sanger sequencing, qPCR or Fluorescence-in-situ-Hybridization) and segregation analysis showed either de novo occurrence or inheritance from an also (mildly) affected parent. In accordance with previously described patients, almost all individuals reported here show developmental delay (22/23), learning disability or ID (22/23), behavioral abnormalities (20/23), weight problems (13/23) and characteristic craniofacial features (i.e. large ears/earlobes, prominent eyebrows, anteverted nares and long philtrum (23/23)). To further investigate the facial gestalt of individuals with CHUJANS, we performed facial analysis using the GestaltMatcher approach. By this, we could establish that PHIP patients are indistinguishable based on the type of PHIP alteration (e.g. missense, loss-of-function, splice site) but show a significant difference to the average face of healthy individuals as well as to individuals with Prader-Willi syndrome (PWS, OMIM #176270) or with a CUL4B-alteration (Intellectual developmental disorder, X-linked, syndromic, Cabezas type, OMIM #300354). Our findings expand the mutational and clinical spectrum of CHUJANS. We discuss the molecular and clinical features in comparison to the published individuals. The fact that some variants were inherited from a mildly affected parent further illustrates the variability of the associated phenotype and outlines the importance of a thorough clinical evaluation combined with genetic analyses for accurate diagnosis and counselling.

Keywords