Genotype-Phenotype Associations in 72 Adults with Suspected ALPL-Associated Hypophosphatasia
Standard
Genotype-Phenotype Associations in 72 Adults with Suspected ALPL-Associated Hypophosphatasia. / Jandl, Nico Maximilian; Schmidt, Tobias; Rolvien, Tim; Stürznickel, Julian; Chrysostomou, Konstantin; von Vopelius, Emil; Volk, Alexander E; Schinke, Thorsten; Kubisch, Christian; Amling, Michael; Barvencik, Florian.
In: CALCIFIED TISSUE INT, Vol. 108, No. 3, 03.2021, p. 288-301.Research output: SCORING: Contribution to journal › SCORING: Journal article › Research › peer-review
Harvard
APA
Vancouver
Bibtex
}
RIS
TY - JOUR
T1 - Genotype-Phenotype Associations in 72 Adults with Suspected ALPL-Associated Hypophosphatasia
AU - Jandl, Nico Maximilian
AU - Schmidt, Tobias
AU - Rolvien, Tim
AU - Stürznickel, Julian
AU - Chrysostomou, Konstantin
AU - von Vopelius, Emil
AU - Volk, Alexander E
AU - Schinke, Thorsten
AU - Kubisch, Christian
AU - Amling, Michael
AU - Barvencik, Florian
PY - 2021/3
Y1 - 2021/3
N2 - Hypophosphatasia (HPP) is a rare inborn error of metabolism due to a decreased activity of tissue nonspecific alkaline phosphatase (TNSALP). As the onset and severity of HPP are heterogenous, it can be challenging to determine the pathogenicity of detected rare ALPL variants in symptomatic patients. We aimed to characterize patients with rare ALPL variants to propose which patients can be diagnosed with adult HPP. We included 72 patients with (1) clinical symptoms of adult HPP or positive family history and (2) low TNSALP activity and/or high pyridoxal 5'-phosphate (PLP) levels, who underwent ALPL gene sequencing. The patients were analyzed and divided into three groups depending on ALPL variant pathogenicity according to the classification of the American College of Medical Genetics and Genomics (ACMG). Reported pathogenic (n = 34 patients), rare (n = 17) and common (n = 21) ALPL variants only were found. Muscular complaints were the most frequent symptoms (> 80%), followed by bone affection (> 50%). Tooth involvement was significantly more common in patients with pathogenic or rare ALPL variants. Seven rare variants could be classified as likely pathogenic (ACMG class 4) of which five have not yet been described. Inconclusive genetic findings and less specific symptoms make diagnosis difficult in cases where adult HPP is not obvious. As not every pathogenic or rare ALPL variant leads to a manifestation of HPP, only patients with bone complications and at least one additional complication concerning teeth, muscle, central nervous and mental system, repeated low TNSALP activity and high PLP levels should be diagnosed as adult HPP if rare ALPL gene variants of ACMG class 4 or higher support the diagnosis.
AB - Hypophosphatasia (HPP) is a rare inborn error of metabolism due to a decreased activity of tissue nonspecific alkaline phosphatase (TNSALP). As the onset and severity of HPP are heterogenous, it can be challenging to determine the pathogenicity of detected rare ALPL variants in symptomatic patients. We aimed to characterize patients with rare ALPL variants to propose which patients can be diagnosed with adult HPP. We included 72 patients with (1) clinical symptoms of adult HPP or positive family history and (2) low TNSALP activity and/or high pyridoxal 5'-phosphate (PLP) levels, who underwent ALPL gene sequencing. The patients were analyzed and divided into three groups depending on ALPL variant pathogenicity according to the classification of the American College of Medical Genetics and Genomics (ACMG). Reported pathogenic (n = 34 patients), rare (n = 17) and common (n = 21) ALPL variants only were found. Muscular complaints were the most frequent symptoms (> 80%), followed by bone affection (> 50%). Tooth involvement was significantly more common in patients with pathogenic or rare ALPL variants. Seven rare variants could be classified as likely pathogenic (ACMG class 4) of which five have not yet been described. Inconclusive genetic findings and less specific symptoms make diagnosis difficult in cases where adult HPP is not obvious. As not every pathogenic or rare ALPL variant leads to a manifestation of HPP, only patients with bone complications and at least one additional complication concerning teeth, muscle, central nervous and mental system, repeated low TNSALP activity and high PLP levels should be diagnosed as adult HPP if rare ALPL gene variants of ACMG class 4 or higher support the diagnosis.
U2 - 10.1007/s00223-020-00771-7
DO - 10.1007/s00223-020-00771-7
M3 - SCORING: Journal article
C2 - 33191482
VL - 108
SP - 288
EP - 301
JO - CALCIFIED TISSUE INT
JF - CALCIFIED TISSUE INT
SN - 0171-967X
IS - 3
ER -