Autosomal recessive Alport syndrome caused by a novel COL4A4 compound heterozygous mutation: A case report

Abstract Glanzmann thrombasthenia (GT) is a homozygous or compound heterozygous autosomal recessive bleeding disorder caused by the qualitative or quantitative deficiency of integrin GPIIb-IIIa, which acts as the receptor of platelet fibrinogen. Here we report a case of GT with a compound heterozygous mutation in GPIIb according to the results of flow cytometry and genetic investigation.The flow cytometry was used to measure the average amounts of integrin GPIIb-IIIa on the patient’s platelets, and all 30 exons of GPIIb were amplified and sequenced with the corresponding primers.The average fluorescence intensity of integrin GPIIb-IIIa were 3.07 and 12.5, respectively, compared with 23.7 and 254, respectively, in the normal healthy individuals. And sequencing analysis of all exons of GPIIb demonstrated that there existed following compound heterozygous mutations in GPIIb gene: one heterozygote mutation (68 C→A) in the 1st exon, which resulted in Pro 23 His substitution in signal peptide domain; one nonsense heterozygous mutation (1750 C→T) in the 17th exon, which result in premature termination; one heterozygote mutation (2159 T→C) in the 21stexon, which resulted in Leu 720 Pro substitution. According to Glanzmann thrombasthenia database of ISTH (http://sinaicentral.mssm.edu/intranet/research/glanzmann/listmutations?mut=GPIIb), 68 C→A mutation and 2159 T→C mutation are novel mutations in the GPIIb heavy chain. These compound heterozygous mutations in GPIIb gene might be a novel pathogenetic mechanism of GT, which impaired the protein translation and co-expression with GPIIIa on the membrane of platelet.

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Immunodeficiency and severe gastrointestinal manifestations in a patient with novel DKC1 mutations causing Hoyeraal–Hreidarsson syndrome

LymphoSign Journal ◽

10.14785/lymphosign-2016-0006 ◽

2016 ◽

Vol 3 (3) ◽

pp. 119-126 ◽

Cited By ~ 1

Author(s):

Nufar Marcus

Keyword(s):

Case Report ◽

Cell Function ◽

Novel Mutation ◽

Severe Combined Immunodeficiency ◽

Compound Heterozygous Mutation ◽

Heterozygous Mutation ◽

Compound Heterozygous ◽

Combined Immunodeficiency ◽

Gastrointestinal Manifestations ◽

Over Time

Background: Hoyeraal–Hreidarsson syndrome (HHS) is considered a clinically severe variant of dyskeratosis congenita (DKC) and represents the extreme phenotype caused by aberrant telomere biology. Unlike patients with DKC who present later in life, most cases of HHS present in the first years of life. Clinical features include intrauterine growth restriction and microcephaly, which are universal but not pathognomonic, as well as gastrointestinal, immunological and neurological manifestations. The immunological profile is varied as a result of cellular immunodeficiency, humoral defects, or both, and may be the presenting symptom of these patients. Moreover, the immunological phenotype can change over time, making HHS a diagnostic challenge. Methods: This case report highlights the clinical presentation and immune investigations of a male patient with a novel mutation in DKC1, causing HHS. Results: Here, we describe a patient with HHS who presented with Pneumocystis jiroveci pneumonia and low T cells, which is typical of severe combined immunodeficiency. Over time, he developed agammaglobulinemia whereas T-cell function improved. He also presented with extremely severe gastrointestinal manifestations, and died at 3 years of age. Conclusion: This case report highlights a novel compound heterozygous mutation in DKC1, and the need to consider HHS as the differential diagnosis of patients with combined immunodeficiency. Statement of novelty: The case reports on a novel mutation in DKC1.

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