Ian D Krantz

The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States

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Publications (222)

  • Source
    Full-text Article · Jul 2016 · The American Journal of Human Genetics
  • Devanshi Mehta · Sarah E. Noon · Emily Schwartz · [...] · Ian D. Krantz
    [Show abstract] [Hide abstract] ABSTRACT: Hearing loss is a relatively common condition in children, occurring in approximately 2 out of every 1,000 births with approximately 50% of reported diagnoses having a primary genetic etiology. Given the prevalence and genetic component of hearing loss, coupled with a trend toward early diagnosis with the institution of universal newborn hearing screening, The Genetics of Hearing Loss Clinic was established at The Children's Hospital of Philadelphia to manage the diagnosis, testing, and genetic counseling for individuals and families. This paper described a cohort of 660 individuals with a diagnosis of hearing loss evaluated between July 2008 and July 2015 in the Genetics of Hearing Loss Clinic. To elucidate the cause of hearing loss in this cohort for better management and prognostication, testing included single nucleotide polymorphism chromosomal microarray, hearing loss next generation sequencing panel, and additional clinical tests inclusive of thyroid and renal function studies, temporal bone magnetic resonance imaging, and electrocardiogram. Of those evaluated, most had bilateral sensorineural hearing loss, occurring in 489/660 (74%). Additionally, 612/660 (93%) of patients presented with a nonsyndromic form of hearing loss (no other observed clinical findings at the time of exam), of which pathogenic mutations in GJB2 were most prevalent. Of the individuals with syndromic manifestations (48/660), Usher and Waardenburg syndrome were most commonly observed. A family history of hearing loss (first degree relative) was present in 12.6% of families with available information. Through molecular analyses, clinical examination, and laboratory testing, a definitive etiologic diagnosis was established in 157/660 (23.8%) of individuals. © 2016 Wiley Periodicals, Inc.
    Article · Jul 2016 · American Journal of Medical Genetics Part A
  • Article · Jun 2016
  • [Show abstract] [Hide abstract] ABSTRACT: Pallister-Killian syndrome (PKS) is a rare sporadic multi-systemic developmental disorder caused by a mosaic tetrasomy of the short arm of chromosome 12. A wide range of clinical characteristics including intellectual disability, seizures, and congenital malformations has previously been described. Individuals with PKS show a characteristic facial phenotype with frontal bossing, alopecia, sparse eyebrows, depressed nasal bridge, long philtrum, telecanthus, and posteriorly rotated ears. Oro-dental features, such as "Pallister lip," macroglossia, delayed eruption of primary teeth, high arched-palate, prognathism, and cleft palate have been occasionally reported in the medical literature. The aim of the study was to assess the oro-dental phenotype of PKS and to describe the oral health status in a cohort participating in the First European Workshop on PKS. A clinical dental examination was performed in 21 Caucasian probands and data regarding medical and dental history collected. Twelve probands (57%) showed an atypical dental pattern, with multiple missing teeth (primarily the first permanent molars) and 2 (10%) a double teeth. The severity of gingivitis and dental caries increased with age and gingival overgrowth was a common finding. A characteristic occlusive phenotype was found: a high-arched palate with mandibular prognathism associated with an anterior openbite and crossbite and with posterior crossbite (unilateral or bilateral). The prevalence of oral habits (non-nutritive sucking, mouth breathing, bruxism) was high, even in older probands. This study suggests that individuals affected by PKS should be observed closely for oro-dental diseases and a multidisciplinary approach is needed to implement the right preventive measures. © 2016 Wiley Periodicals, Inc.
    Article · Jun 2016 · American Journal of Medical Genetics Part A
  • Yaning Wu · Matthew A. Deardorff · Ian D. Krantz
    Chapter · Jun 2016
  • Chapter · Jun 2016
  • Sarah E. Noon · Matthew A. Deardorff · Ian D. Krantz
    [Show abstract] [Hide abstract] ABSTRACT: The cover, by Ian D. Krantz, features a composite image from several of his articles including the Introduction Dr. Laird G. Jackson Festschrift, DOI: 10.1002/ajmg.c.31499.
    Article · Jun 2016 · American Journal of Medical Genetics Part C Seminars in Medical Genetics
  • Sarah Bowdin · Adel Gilbert · Emma Bedoukian · [...] · Ian D. Krantz
    [Show abstract] [Hide abstract] ABSTRACT: The introduction of diagnostic clinical genome and exome sequencing (CGES) is changing the scope of practice for clinical geneticists. Many large institutions are making a significant investment in infrastructure and technology, allowing clinicians to access CGES, especially as health-care coverage begins to extend to clinically indicated genomic sequencing-based tests. Translating and realizing the comprehensive clinical benefits of genomic medicine remain a key challenge for the current and future care of patients. With the increasing application of CGES, it is necessary for geneticists and other health-care providers to understand its benefits and limitations in order to interpret the clinical relevance of genomic variants identified in the context of health and disease. New, collaborative working relationships with specialists across diverse disciplines (e.g., clinicians, laboratorians, bioinformaticians) will undoubtedly be key attributes of the future practice of clinical genetics and may serve as an example for other specialties in medicine. These new skills and relationships will also inform the development of the future model of clinical genetics training curricula. To address the evolving role of the clinical geneticist in the rapidly changing climate of genomic medicine, two Clinical Genetics Think Tank meetings were held that brought together physicians, laboratorians, scientists, genetic counselors, trainees, and patients with experience in clinical genetics, genetic diagnostics, and genetics education. This article provides recommendations that will guide the integration of genomics into clinical practice.Genet Med advance online publication 12 May 2016Genetics in Medicine (2016); doi:10.1038/gim.2016.17.
    Article · May 2016 · Genetics in Medicine
  • [Show abstract] [Hide abstract] ABSTRACT: There is an abundance of information in the literature on patient experiences with Internet support groups (ISGs). However, studies exploring these experiences in a rare disease population are scarce, even though these families are often at a disadvantage for resources, reliable information, and support. The aim of the current study was to explore the experiences with ISGs for parents of children with Cornelia de Lange syndrome (CdLS), a rare genetic diagnosis, in order to better understand the impact on emotional support and their child's medical care. Focus groups were conducted to inform the design of a large-scale internet survey. The survey asked parents closed- and open-ended questions regarding experiences with ISGs, with a focus on the psychosocial, medical, and logistical aspects. The survey found that 141/170 (82.6%) respondents have visited an Internet-based support group to find support or information about their child's CdLS diagnosis. The majority of respondents (71.7%) reported that ISGs have been helpful in finding emotional support, with the most common areas impacted as a result of ISG participation being behavior toward their children and family dynamic. Regarding medical care, most respondents (63.9%) reported that ISGs have been helpful in finding medical information and support, with the most commonly impacted areas of their child's care including day-to-day management, diet, therapy interventions, and healthcare providers. These findings provide a greater understanding of the role of Internet networking in healthcare and may inform future approaches to medical care and psychosocial support for rare, complex genetic diagnoses. © 2016 Wiley Periodicals, Inc.
    Article · May 2016 · American Journal of Medical Genetics Part C Seminars in Medical Genetics
  • [Show abstract] [Hide abstract] ABSTRACT: Given the clinical complexities of Cornelia de Lange Syndrome (CdLS), the Center for CdLS and Related Diagnoses at The Children's Hospital of Philadelphia (CHOP) and The Multidisciplinary Clinic for Adolescents and Adults at Greater Baltimore Medical Center (GBMC) were established to develop a comprehensive approach to clinical management and research issues relevant to CdLS. Little work has been done to evaluate the general utility of a multispecialty approach to patient care. Previous research demonstrates several advantages and disadvantages of multispecialty care. This research aims to better understand the benefits and limitations of a multidisciplinary clinic setting for individuals with CdLS and related diagnoses. Parents of children with CdLS and related diagnoses who have visited a multidisciplinary clinic (N = 52) and who have not visited a multidisciplinary clinic (N = 69) were surveyed to investigate their attitudes. About 90.0% of multispecialty clinic attendees indicated a preference for multidisciplinary care. However, some respondents cited a need for additional clinic services including more opportunity to meet with other specialists (N = 20), such as behavioral health, and increased information about research studies (N = 15). Travel distance and expenses often prevented families' multidisciplinary clinic attendance (N = 41 and N = 35, respectively). Despite identified limitations, these findings contribute to the evidence demonstrating the utility of a multispecialty approach to patient care. This approach ultimately has the potential to not just improve healthcare for individuals with CdLS but for those with medically complex diagnoses in general. © 2016 Wiley Periodicals, Inc.
    Article · May 2016 · American Journal of Medical Genetics Part C Seminars in Medical Genetics
  • Sarah E. Noon · Matthew A. Deardorff · Ian D. Krantz
    Article · May 2016 · American Journal of Medical Genetics Part C Seminars in Medical Genetics
  • [Show abstract] [Hide abstract] ABSTRACT: Despite rapid technical progress and demonstrable effectiveness for some types of diagnosis and therapy, much remains to be learned about clinical genome and exome sequencing (CGES) and its role within the practice of medicine. The Clinical Sequencing Exploratory Research (CSER) consortium includes 18 extramural research projects, one National Human Genome Research Institute (NHGRI) intramural project, and a coordinating center funded by the NHGRI and National Cancer Institute. The consortium is exploring analytic and clinical validity and utility, as well as the ethical, legal, and social implications of sequencing via multidisciplinary approaches; it has thus far recruited 5,577 participants across a spectrum of symptomatic and healthy children and adults by utilizing both germline and cancer sequencing. The CSER consortium is analyzing data and creating publically available procedures and tools related to participant preferences and consent, variant classification, disclosure and management of primary and secondary findings, health outcomes, and integration with electronic health records. Future research directions will refine measures of clinical utility of CGES in both germline and somatic testing, evaluate the use of CGES for screening in healthy individuals, explore the penetrance of pathogenic variants through extensive phenotyping, reduce discordances in public databases of genes and variants, examine social and ethnic disparities in the provision of genomics services, explore regulatory issues, and estimate the value and downstream costs of sequencing. The CSER consortium has established a shared community of research sites by using diverse approaches to pursue the evidence-based development of best practices in genomic medicine.
    Article · May 2016 · The American Journal of Human Genetics
  • Source
    Maria Ramos · Alisha Wilkens · Ian D Krantz · Yaning Wu
    [Show abstract] [Hide abstract] ABSTRACT: Distal deletion of the long arm of chromosome 10 with breakpoints mapped at 10q26 is a well-recognized contiguous genomic disorder. A wide spectrum of clinical findings is seen in affected individuals and the common clinical features include craniofacial dysmorphia, developmental delay, intellectual disability, hypotonia, cardiovascular defects, and urogenital malformations. We report herein on a male patient with a 5.5 Mb interstitial deletion of 10q26.11q2613 and compare his clinical presentation to previously reported cases. Apart from characteristic phenotypes seen in 10q26 deletion syndrome, he presents with colobomas and left ventricle enlargement. These are cardiovascular and ophthalmological findings that have not been described in prior cases. © 2016 Wiley Periodicals, Inc.
    Full-text Article · Apr 2016 · American Journal of Medical Genetics Part C Seminars in Medical Genetics
  • Maninder Kaur · Devanshi Mehta · Sarah E Noon · [...] · Ian D Krantz
    [Show abstract] [Hide abstract] ABSTRACT: Cornelia de Lange syndrome (CdLS) is a rare, genetically heterogeneous multisystem developmental disorder with a high degree of variability in its clinical presentation. Approximately 65% of probands harbor mutations in genes that encode core components (SMC1A, SMC3, and RAD21) or regulators (NIPBL, HDAC8) of the cohesin complex, of which mutations in NIPBL are the most common. Cohesin plays a canonical role in sister chromatid cohesion during cell division and non-canonical roles in DNA repair, stem cell maintenance and differentiation, and regulation of gene expression. Disruption of the latter role seems to be the major contributor to the underlying molecular pathogenesis of CdLS. NIPBL is required for loading and unloading the cohesin complex onto chromosomes. The expression levels of NIPBL itself appear to be tightly regulated and highly evolutionarily conserved. Droplet digital PCR was used to quantify NIPBL mRNA expression levels with high precision from a cohort of 37 samples (NIPBL, SMC1A, SMC3, and HDAC8 mutation positive probands and negative control). Probands with severe forms of CdLS or severe mutation types were found to have lower levels of NIPBL in comparison to phenotypically milder patients and controls. Levels of NIPBL also correlated with the presence of mutations in different CdLS-causing genes. The data suggests that NIPBL levels are closely correlated with the severity of CdLS and with specific causative genes and types of mutations. ddPCR may provide a tool to assist in diagnostic approaches to CdLS, for genetic counseling and prognosis, and for monitoring potential therapeutic modalities in the future. © 2016 Wiley Periodicals, Inc.
    Article · Apr 2016 · American Journal of Medical Genetics Part C Seminars in Medical Genetics
  • [Show abstract] [Hide abstract] ABSTRACT: Cornelia de Lange syndrome (CdLS) is a well-described multisystem developmental disorder characterized by dysmorphic facial features, growth and behavioral deficits, and cardiac, gastrointestinal, and limb anomalies. The limb defects seen in CdLS can be mild, with small feet or hands only, or can be severe, with variable deficiency defects involving primarily the ulnar structures and ranging from mild hypoplasia of the fifth digit to complete absence of the forearm. Interestingly, the upper limbs are typically much more involved than the lower extremities that generally manifest with small feet and 2-3 syndactyly of the toes and shortened fourth metatarsal. The upper limbs often manifest asymmetric involvement. The limb findings in our cohort of 378 individuals with CdLS demonstrate a consistent pattern of laterality and symmetry involvement (with increased severity of right-sided limb in individuals with asymmetric limb defects) and a correlation of more significant limb defects with an increased risk of other structural anomalies, and more severe behavioral outcomes. Additionally, we found that individuals with mutations in NIPBL were most likely to have limb defects compared to mutations in other genes with nonsense, exonic deletion, and frameshift mutations being most prevalent in those with limb defects. Characterization of the limb differences in children with CdLS may provide a tool to assist in genetic counseling and determining prognosis. This paper will review the limb involvement in a large cohort of individuals with CdLS assessing the correlation with molecular etiologies, symmetry, additional structural birth defects, and cognitive outcomes. © 2016 Wiley Periodicals, Inc.
    Article · Apr 2016 · American Journal of Medical Genetics Part C Seminars in Medical Genetics
  • Olivia L Katz · Ian D Krantz · Sarah E Noon
    [Show abstract] [Hide abstract] ABSTRACT: This report describes a male child with a history of poor feeding and swallowing problems, hypotonia, mild bilateral sensorineural hearing loss, cerebral cortical agenesis, cardiac defects, cyanotic episodes triggered by specific movement, dysmorphic features, and developmental delays. Analysis by CytoScan HD array identified a 12.1 Mb interstitial deletion of 7q22.1q31.1 (98,779,628-110,868,171). We present a comprehensive review of the literature surrounding intermediate 7q deletions that overlap with this child's deletion, and an analysis of candidate genes in the deleted region. © 2016 Wiley Periodicals, Inc.
    Article · Apr 2016 · American Journal of Medical Genetics Part C Seminars in Medical Genetics
  • Source
    Jianhua Zhao · Sarah E Noon · Ian D Krantz · Yaning Wu
    [Show abstract] [Hide abstract] ABSTRACT: We report on a 4-year-old female who presented with unilateral sensorineural hearing loss and a concern for developmental delay. A genome-wide SNP array analysis was performed and revealed a de novo 3.2 Mb interstitial deletion of chromosome 7q31.2q31.31. This region contains thirteen protein-encoding genes. It is unknown whether haploinsufficiency of any of these genes is responsible for the clinical features of our patient. We reviewed, the clinical phenotype of a previously published 7q31.3 deletion patient and 18 additional patients with overlapping 7q31 deletions listed in the DECIPHER database. The most consistent feature in these patients and our proband is delayed speech and language development. Hearing loss is presented both in our proband and the published 7q31.3 patient. Our study suggests that a small region on chromosome 7q31.3 encompassing four genes, CFTR, CTTNBP2, NAA38, and ANKRD7, may represent a new locus for congenital hearing loss and/or speech development. © 2016 Wiley Periodicals, Inc.
    Full-text Article · Apr 2016 · American Journal of Medical Genetics Part C Seminars in Medical Genetics
  • Source
    Katsunori Fujiki · Katsuhiko Shirahige · Maninder Kaur · [...] · Kosuke Izumi
    [Show abstract] [Hide abstract] ABSTRACT: Figure S2. 12p copy number analysis with buccal swab DNA samples from control individuals. Y‐axis represents the ddPCR results. Error bars indicate ±2 SD.
    Full-text Dataset · Jan 2016
  • Katsunori Fujiki · Katsuhiko Shirahige · Maninder Kaur · [...] · Kosuke Izumi
    [Show abstract] [Hide abstract] ABSTRACT: 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 the diagnosis of PKS. Methods: The utility of the droplet digital PCR system in quantifying the mosaic ratio of isochromosome 12p in PKS was evaluated. Results: Droplet digital PCR was able to precisely quantify isochromosome 12p mosaic ratio, and copy number measured by droplet digital PCR was correlated well with that of fluorescence in situ hybridization analysis. Conclusion: Droplet digital PCR should be considered as an effective tool for both clinical and research analytics to precisely quantify mosaic genomic copy number alterations or mosaic mutations.
    Article · Jan 2016
  • Source
    Katsunori Fujiki · Katsuhiko Shirahige · Maninder Kaur · [...] · Kosuke Izumi
    [Show abstract] [Hide abstract] ABSTRACT: Figure S1. 12p copy number analysis of control individuals. Y‐axis represents the ddPCR results. Error bars indicate ±2 SD.
    Full-text Dataset · Jan 2016

Publication Stats

10k Citations


  • 2003-2004
    • The Children's Hospital of Philadelphia
      • Division of Human Genetics and Molecular Biology
      Philadelphia, Pennsylvania, United States
  • 1998-2000
    • William Penn University
      Filadelfia, Pennsylvania, United States
  • 1997
    • Boston Children's Hospital
      Boston, Massachusetts, United States
    • Stowers Institute for Medical Research
      Kansas City, Kansas, United States
    • University of Washington Seattle
      Seattle, Washington, United States