M. J. E. Kempers
University of Amsterdam
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Featured researches published by M. J. E. Kempers.
The Journal of Clinical Endocrinology and Metabolism | 2012
Nils Krone; Nicole Reisch; Jan Idkowiak; Vivek Dhir; Hannah E Ivison; Beverly Hughes; Ian T. Rose; Donna M. O'Neil; Raymon Vijzelaar; Matthew J. Smith; Fiona MacDonald; Trevor R. Cole; Nicolai Adolphs; John S. Barton; Edward Blair; Stephen R. Braddock; Felicity Collins; Deborah L. Cragun; Mehul T. Dattani; Ruth Day; Shelley Dougan; Miriam Feist; Michael Gottschalk; John Welbourn Gregory; Michaela Haim; Rachel Harrison; Anne Haskins Olney; Berthold P. Hauffa; Peter C. Hindmarsh; Robert J. Hopkin
Context: P450 oxidoreductase deficiency (PORD) is a unique congenital adrenal hyperplasia variant that manifests with glucocorticoid deficiency, disordered sex development (DSD), and skeletal malformations. No comprehensive data on genotype-phenotype correlations in Caucasian patients are available. Objective: The objective of the study was to establish genotype-phenotype correlations in a large PORD cohort. Design: The design of the study was the clinical, biochemical, and genetic assessment including multiplex ligation-dependent probe amplification (MLPA) in 30 PORD patients from 11 countries. Results: We identified 23 P450 oxidoreductase (POR) mutations (14 novel) including an exonic deletion and a partial duplication detected by MLPA. Only 22% of unrelated patients carried homozygous POR mutations. p.A287P was the most common mutation (43% of unrelated alleles); no other hot spot was identified. Urinary steroid profiling showed characteristic PORD metabolomes with variable impairment of 17α-hydroxylase and 21-hydroxylase. Short cosyntropin testing revealed adrenal insufficiency in 89%. DSD was present in 15 of 18 46,XX and seven of 12 46,XY individuals. Homozygosity for p.A287P was invariably associated with 46,XX DSD but normal genitalia in 46,XY individuals. The majority of patients with mild to moderate skeletal malformations, assessed by a novel scoring system, were compound heterozygous for missense mutations, whereas nearly all patients with severe malformations carried a major loss-of-function defect on one of the affected alleles. Conclusions: We report clinical, biochemical, and genetic findings in a large PORD cohort and show that MLPA is a useful addition to POR mutation analysis. Homozygosity for the most frequent mutation in Caucasians, p.A287P, allows for prediction of genital phenotype and moderate malformations. Adrenal insufficiency is frequent, easily overlooked, but readily detected by cosyntropin testing.
Clinical Endocrinology | 2002
Bert Bakker; M. J. E. Kempers; Jan J. M. de Vijlder; David A. van Tijn; B. M. Wiedijk; Michael Van Bruggen; Thomas Vulsma
objective The dynamics of the plasma concentrations of various diagnostic determinants of thyroid function were analysed in children with congenital hypothyroidism (CH) after the start of T4 supplementation. The description of the biochemical dynamics of TSH and free T4 (FT4) during the first period of thyroxine treatment is important to depict the practical outlines of the initial dosage of T4 and dosage adjustments for newborns with variable forms of CH.
The Journal of Clinical Endocrinology and Metabolism | 2008
L. van der Sluijs Veer; M. J. E. Kempers; Thomas Vulsma; Martha A. Grootenhuis
CONTEXTnWith advances in the treatment of congenital hypothyroidism (CH), the neuropsychological functioning of CH patients is considerably improved. Although much is written about cognitive and motor development, little is known about emotional and social consequences for patients growing up with CH, diagnosed by neonatal screening.nnnOBJECTIVESnThe objectives of the study were to: 1) compare health-related quality of life (HRQoL), developmental milestones also called course of life (CoL), sociodemographical outcomes, and self-esteem of CH patients with the general population; and 2) explore whether severity of CH was related to these outcomes.nnnDESIGN/SETTING/PATIENTSnA total of 69 young adults with CH, born in The Netherlands in 1981-1982, completed the TNO-AZL Questionnaire for Adults Health related Quality of Life questionnaire, the CoL survey (developmental milestones and sociodemographical outcomes), and a self-esteem questionnaire.nnnMAIN OUTCOME MEASURESnHRQoL, CoL, social demographical outcomes, and self-esteem in young adults with CH were determined.nnnRESULTSnCH patients are more often at risk for HRQoL impairment and reported lower HRQoL on several domains (cognitive functioning, P < 0.0001; sleeping, P < 0.004; pain, P < 0.0001; daily activities, P < 0.004; vitality, P < 0.0001; aggressiveness, P < 0.0001; and depressive moods, P < 0.0001) compared with healthy adults. Patients reported a lower self-esteem (P < 0.005) and had a delayed CoL on the domain of social development (P < 0.016). There were no significant within-group differences between the severity groups for HRQoL, CoL, and self-esteem.nnnCONCLUSIONSnNegative consequences in terms of HRQoL, development, and self-esteem are prevalent in young adults with CH. Health care physicians should be attentive to these consequences and provide additional support (emotional and educational guidance) if necessary.
Hormone Research in Paediatrics | 2013
M. J. E. Kempers; S.N. van der Crabben; M. de Vroede; J. Van der Velden; Romana T. Netea-Maier; R.A. Duim; Barto J. Otten; M. Losekoot; Jan M. Wit
Background: Congenital isolated growth hormone deficiency (IGHD) is a rare endocrine disorder that presents with severe proportionate growth failure. Dominant (type II) IGHD is usually caused by heterozygous mutations of GH1. The presentation of newly affected family members in 3 families with dominant IGHD in whom previous genetic testing had not demonstrated a GH1 mutation or had not been performed, prompted us to identify the underlying genetic cause. Methods:GH1 was sequenced in 3 Caucasian families with a clinical autosomal dominant IGHD. Results: All affected family members had severe growth hormone (GH) deficiency that became apparent in the first 2 years of life. GH treatment led to a marked increase in height SDS. So far, no other pituitary dysfunctions have become apparent. In the first family a novel splice site mutation in GH1 was identified (c.172-1G>C, IVS2-1G>C). In two other families a previously reported splice site mutation (c.291+1G>A, IVS3+1G>A) was found. Conclusion: These data show that several years after negative genetic testing it was now possible to make a genetic diagnosis in these families with a well-defined, clearly heritable, autosomal dominant IGHD. This underscores the importance of clinical and genetic follow-up in a multidisciplinary setting. It also shows that even without a positive family history, genetic testing should be considered if the phenotype is strongly suggestive for a genetic syndrome. Identification of pathogenic mutations, like these GH1 mutations, has important clinical implications for the surveillance and genetic counseling of patients and expands our knowledge on the genotype-phenotype correlation.
The Journal of Clinical Endocrinology and Metabolism | 2003
M. J. E. Kempers; David A. van Tijn; A. S. Paul van Trotsenburg; Jan J. M. de Vijlder; B. M. Wiedijk; Thomas Vulsma
The Journal of Clinical Endocrinology and Metabolism | 2006
M. J. E. Kempers; L. van der Sluijs Veer; M.W.G. Nijhuis-Van der Sanden; Libbe Kooistra; B. M. Wiedijk; Irene R. Faber; J.J.M. de Vijlder; Martha A. Grootenhuis; Thomas Vulsma
The Journal of Clinical Endocrinology and Metabolism | 2006
M. J. E. Kempers; Caren I. Lanting; A.F. van Heijst; A.S.P. van Trotsenburg; B. M. Wiedijk; J.J.M. de Vijlder; Thomas Vulsma
The Journal of Clinical Endocrinology and Metabolism | 2007
M. J. E. Kempers; Liesbeth van der Sluijs Veer; Ria Nijhuis-van der Sanden; Caren I. Lanting; Libbe Kooistra; B. M. Wiedijk; Jan J. M. de Vijlder; Martha A. Grootenhuis; Thomas Vulsma
The Journal of Clinical Endocrinology and Metabolism | 2007
M. J. E. Kempers; A. S. Paul van Trotsenburg; Rick R. van Rijn; Anne M. J. B. Smets; Bert J. Smit; Jan J. M. de Vijlder; Thomas Vulsma
The Journal of Clinical Endocrinology and Metabolism | 2005
M. J. E. Kempers; A.S.P. van Trotsenburg; D.A. van Tijn; Erin Bakker; B. M. Wiedijk; E. Endert; J. J. M. De Vijlder; T. Vulsma