second-degree atrioventricular block

An atrioventricular block that is characterized by progressive prolongation of the PR interval on consecutive beats followed by a blocked P wave on electrocardiogram or intermittently non-conducted P waves not preceded by PR changes on electrocardiogram caused by a conduction block between the atria and the ventricles through the atrioventricular node.

DNA ligase IV deficiency

A combined T cell and B cell immunodeficiency that has_material_basis_in a mutation in the LIG4 gene, a DNA ligase, encoding a protein essential for V(D)J recombination and DNA double-strand break (DSB) repair through nonhomologous end joining (NHEJ). Patients present with immunodeficiency and developmental and growth delay.

third-degree atrioventricular block

An atrioventricular block that is characterized by bradycardia, hypotension, hemodynamic instability and complete dissociation between P waves and QRS complexes on electrocardiogram caused when conduction fails to propagate from atria to ventricles.

chromosome 16p12.1 deletion syndrome

A chromosomal deletion syndrome that has_material_basis_in a 520 kb deletion on the short (p) arm of the chromosome at a location designated 16p12.1 and is characterized by developmental delay, craniofacial dysmorphology, and congenital heart defects.

Cri-Du-Chat syndrome

A syndrome that has_material_basis_in deletion of the end of the chromosome 5 p arm and that is characterized by intellectual disability, delayed development, small head size, low birth weight, weak muscle tone widely set eyes, low-set ears, a small jaw, a rounded face and a high-pitched cry that sounds like that of a cat.

congenital disorder of glycosylation Ig

A congenital disorder of glycosylation I that is characterized by facial dysmorphism (prominent forehead, large ears, thin upper lip), generalized hypotonia, feeding difficulties, moderate to severe developmental delay, progressive microcephaly, frequent upper respiratory tract infections due to impaired immunity with decreased immunoglobulin levels, and decreased coagulation factors and has_material_basis_in homozygous or compound heterozygous mutation in the gene encoding dolichyl-P-mannose:Man-7-GlcNAc-2-PP-dolichyl-alpha-6-mannosyltransferase on chromosome 22q13.

congenital disorder of glycosylation Ih

A congenital disorder of glycosylation I that is characterized by gastrointestinal symptoms (diarrhea, vomiting, feeding problems with failure to thrive, protein-losing enteropathy), edema and ascites (including hydrops fetalis), hepatomegaly, renal tubulopathy, coagulation anomalies due to thrombocytopenia, brain involvement (psychomotor delay, seizures, ataxia), facial dysmorphism (low-set ears and retrognathia), pes equinovarus, and muscular hypotonia and has_material_basis_in heterozygous mutation in the gene encoding dolichyl-P-glucose:Glc-1-Man-9-GlcNAc-2-PP-dolichyl-alpha-3-glucosyltransferase on chromosome 11q14.