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Harold Chen

Publications and source records attributed to Harold Chen.

3 recordsLinked to original sources
PubMed2006

Trismus-pseudocamptodactyly syndrome is caused by recurrent mutation of MYH8.

Trismus-pseudocamptodactyly syndrome (TPS) is a rare autosomal dominant distal arthrogryposis (DA) characterized by an inability to open the mouth fully (trismus) and an unusual camptodactyly of the fingers that is apparent only upon dorsiflexion of the wrist (i.e., pseudocamptodactyly). TPS is also known as Dutch-Kentucky syndrome because a Dutch founder mutation is presumed to be the origin of TPS cases in the Southeast US, including Kentucky. To date only a single mutation, p.R674Q, in MYH8 has been reported to cause TPS. Several individuals with this mutation also had a so-called "variant" of Carney complex, suggesting that the pathogenesis of TPS and Carney complex might be shared. We screened MYH8 in four TPS pedigrees, including the original Dutch family in which TPS was reported. All four TPS families shared the p.R674Q substitution. However, haplotype analysis revealed that this mutation has arisen independently in North American and European TPS pedigrees. None of the individuals with TPS studied had features of Carney complex, and p.R674Q was not found in 49 independent cases of Carney complex that were screened. Our findings show that distal arthrogryposis syndromes share a similar pathogenesis and are, in general, caused by disruption of the contractile complex of muscle.

Amino Acid Sequence↗
PubMedDate not supplied

Immune defects in subjects with dysmorphic disorders.

Patients with dysmorphic disorders seem to have frequent respiratory infections that may be attributed to associated anatomic or neurological abnormalities, but immune defects may contribute to their susceptibility to infections. We screened subjects with dysmorphic conditions for major hematologic, B-cell and T-cell defects. We studied 84 subjects with dysmorphic disorders: 29 with chromosomal disorders, 27 with single gene disorders, and 28 with unclassified dysmorphic disorders. They were evaluated by physical examination; medical history suggestive of possible immune deficiency; complete blood count; serum immunoglobulin G (IgG), IgA, and IgM levels; and lymphocyte subsets. Low laboratory values (less than fifth percentile for age) were detected in 54.8%; was highest in the chromosomal disorder group (79.3%) followed by the single gene disorder group (55.6%) and was lowest in the unclassified dysmorphic disorder group (28.6%). The most common low values were in the CD19 and CD16/56 lymphocyte subpopulations followed by IgG and IgA levels. None of the subjects had neutropenia or thrombocytopenia. History of significant recurrent infections was noted in five subjects, all of whom had abnormal laboratory values. The highest frequency of abnormal laboratory values was in Down syndrome followed by Turner syndrome and chromosome deletions. We concluded that patients with dysmorphic disorders, particularly those with chromosomal disorders, have a high frequency of various B-cell and T-cell defects that may be contributing to their susceptibility to infection. Studies are needed to further delineate the immunologic defects in that population and to investigate a possible genetic basis at the molecular level.

Adolescent↗