Autosomal dominant hypercholesterolemia (ADH) is associated with mutations in the low-density lipoprotein (LDL) receptor (LDLR), apolipoprotein B (APOB), and proprotein convertase subtilisin/kexin 9 (PCSK9) genes, and it is estimated to be greatly underdiagnosed.
In an effort to elucidate the CaSR's skeletal role, bone tissue and material characteristics from patients with autosomal dominant hypocalcemia (ADH), a genetic form of primary hypoparathyroidism caused by CASR gain-of-function mutations, were compared to patients with postsurgical hypoparathyroidism (PSH).
Autosomal dominant hypercholesterolemia (ADH) is associated with mutations in the low-density lipoprotein (LDL) receptor (LDLR), apolipoprotein B (APOB), and proprotein convertase subtilisin/kexin 9 (PCSK9) genes, and it is estimated to be greatly underdiagnosed.
Autosomal dominant hypercholesterolemia (ADH) is associated with mutations in the low-density lipoprotein (LDL) receptor (LDLR), apolipoprotein B (APOB), and proprotein convertase subtilisin/kexin 9 (PCSK9) genes, and it is estimated to be greatly underdiagnosed.
An analysis of CaSR mutations identified in >300 hypercalcaemic and hypocalcaemic probands revealed five 'disease-switch' residues (Gln27, Asn178, Ser657, Ser820 and Thr828) that are affected by FHH and ADH mutations.
The human calcium-sensing receptor (<i>CASR</i>) is the key controller of extracellular Ca<sub>o</sub><sup>2+</sup> homeostasis, and different mutations in the <i>CASR</i> gene have been linked to different calcium diseases, such as familial hypocalciuric hypercalcemia, severe hyperparathyroidism, autosomal-dominant hypocalcemia (ADH), and Bartter's syndrome type V. In this study, two generations of a family with biochemically and clinically confirmed ADH who suffered severe muscle pain, arthralgia, tetany, abdominal pain, and fatigue were evaluated for mutations in the <i>CASR</i> gene.
Thus, studies of FHH- and ADH-associated mutations have revealed novel steps by which CASR mediates signalling and compartmental bias, and these pathways could provide new targets for therapies for patients with calcaemic disorders.
We included a total of 119 individuals; 34 bi-allelic ADH mutation carriers (20 homozygous/compound heterozygous LDLR mutation carriers (HoFH), 2 homozygous APOB mutation carriers (HoFDB), and 12 double heterozygotes for an LDLR and APOB mutation), 63 mono-allelic ADH mutation carriers (50 heterozygous LDLR [HeFH], 13 heterozygous APOB [HeFDB] mutation carriers), and 22 unaffected family members.
We included a total of 119 individuals; 34 bi-allelic ADH mutation carriers (20 homozygous/compound heterozygous LDLR mutation carriers (HoFH), 2 homozygous APOB mutation carriers (HoFDB), and 12 double heterozygotes for an LDLR and APOB mutation), 63 mono-allelic ADH mutation carriers (50 heterozygous LDLR [HeFH], 13 heterozygous APOB [HeFDB] mutation carriers), and 22 unaffected family members.
Genetic analysis of the CaSR gene was performed in a patient who presented in the neonatal period with hypocalcemic seizures and biochemical features of ADH.
Our objective was to determine the frequency of p.Leu167del mutation in APOE gene in subjects with autosomal dominant hypercholesterolemia (ADH) in whom LDLR, APOB, and PCSK9 mutations had been excluded and to identify the mechanisms by which this mutant apo E causes hypercholesterolemia.
Compared to control cells, cells originally derived from an individual with ADH (HLC-S127R) secreted less PCSK9 in the media (-38.5%; P=0.038) and had a 71% decrease (P<0.001) of low-density lipoprotein (LDL) uptake, whereas cells originally derived from an individual with FHBL (HLC-R104C/V114A) displayed a strong decrease in PCSK9 secretion (-89.7%; P<0.001) and had a 106% increase (P=0.0104) of LDL uptake.
However, CASR mutations are only detected in ≤70% of FHH and ADH cases, referred to as FHH type 1 and ADH type 1, respectively, and studies in other FHH and ADH kindreds have revealed these disorders to be genetically heterogeneous.
Therefore, even though LDLR mutations are the major cause of ADH with a large mutation spectrum, APOE variants were found to be significantly associated with the disease.
This study sought to assess the risk of premature CHD in ADH patients with mutations in LDLR (referred to as familial hypercholesterolemia [FH]) vs those without detectable mutations (unexplained ADH), stratified by sex.