Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026827 (hypotonia)
 5,860 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Wolf-Hirschhorn syndrome (WHS) is characterized by growth delay, developmental delay, hypotonia, seizures, feeding difficulties, and characteristic facial features. Deletion of either of two critical regions (WHSCR and WHSCR-2) within chromosome band 4p16.3 has been proposed as necessary for the minimal clinical manifestations of WHS and controversy remains regarding their designation. We describe two patients with novel terminal microdeletions in 4p16.3 who lack the characteristic facial features but do show some of the more nonspecific manifestations of WHS. The first patient had a ring chromosome 4 with an intact 4q subtelomere and a terminal 4p microdeletion of approximately 1.27-1.46 Mb. This deletion was distal to both proposed critical regions. The second patient had a normal karyotype with a terminal 4p microdeletion of approximately 1.78 Mb. This deletion was distal to WHSCR and the breakpoint was near or within the known distal boundary for WHSCR-2. Both patients showed significant postnatal growth delay, mild developmental delays and feeding difficulties. Their facial features were not typical for WHS. The phenotype of the first patient may have been influenced by the presence of a ring chromosome. Seizures were absent in the first patient whereas the second patient had a complex seizure disorder. Characterization of these patients supports the hypothesis that a gene in WHSCR-2, LETM1, plays a direct role in seizure development, and demonstrates that components of the WHS phenotype can be seen with deletions distal to the known boundaries of the two proposed critical regions. These patients also emphasize the difficulty of mapping clinical manifestations common to many aneusomy syndromes.
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PMID:Two unique patients with novel microdeletions in 4p16.3 that exclude the WHS critical regions: implications for critical region designation. 1769 24

Wolf-Hirschhorn syndrome (WHS) is a well-known multiple congenital anomalies/mental retardation syndrome, firstly described in 1961 by Cooper and Hirschhorn. Its frequency is estimated as 1/50,000-1/20,000 births, with a female predilection of 2:1. The disorder is caused by partial loss of material from the distal portion of the short arm of chromosome 4 (4p16.3), and is considered a contiguous gene syndrome. No single gene deletions or intragenic mutations have been shown to confer the full WHS phenotype. Since the disorder was brought to the attention of geneticists, many additional cases have been published. Only in 1999, however, were the first data on the natural history brought to the attention of the medical community. The purpose of the present study is to help delineate in more detail and over a longer period of time, the natural history of WHS, in order to establish appropriate health supervision and anticipatory guidance for individuals with this disorder. We have collected information on 87 patients diagnosed with WHS (54 females and 33 males) both in USA and Italy. Age at first observation ranged between newborn and 17 years. Twenty patients have been followed from 4 months to 23 years. The deletion proximal breakpoint varied from 4p15.32 to 4p16.3, and, by FISH, was terminal and included both WHSCR. Deletion was detected by standard cytogenetics in 44/87 (50.5%) patients, whereas FISH was necessary in the other 43 (49.5%). Array-CGH analysis at 1 Mb resolution was performed in 34/87 patients, and, in 15/34 (44%), showed an unbalanced translocation leading to both a 4p monosomy and a partial trisomy for another chromosome arm. Six more patients had been previously shown to have an unbalanced translocation by karyotype analysis or FISH with a WHS-specific probe. Sixty-five of 87 patients had an apparent pure, de novo, terminal deletion; and 1/87 a tandem duplication of 4p16.1p16.3 associated with 4p16.3pter deletion. Age at diagnosis varied between 7 months gestation and 16 years. Ninety-three percent had a seizure disorder with a good outcome; 80% had prenatal onset growth deficiency followed by short stature and slow weight gain; 60% had skeletal anomalies; 50% had heart lesions; 50% had abnormal tooth development; and 40% had hearing loss. Distinctive EEG findings were seen in 90%. Structural CNS anomalies were detected in 80%. Global developmental delay of varying degrees was present in all patients. Almost 50% was able to walk either alone or with support. Hypotonia was present in virtually all patients. A global improvement was observed in all individuals, over time. Our survey has also shown how the characteristic facial phenotype tends to be less pronounced in those patients with a smaller deletion, and microcephaly is not observed in the patients with certain cryptic unbalanced translocations.
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PMID:Update on the clinical features and natural history of Wolf-Hirschhorn (4p-) syndrome: experience with 87 patients and recommendations for routine health supervision. 1893 24