Familial translocation resulting in Wolf-Hirschhorn syndrome in two related unbalanced individuals: clinical evaluation of a 39-year-old man with Wolf-Hirschhorn syndrome

Mouse model implicates GNB3 duplication in a childhood obesity syndrome

Obesity is a highly heritable condition and a risk factor for other diseases, including type 2 diabetes, cardiovascular disease, hypertension, and cancer. Recently, genomic copy number variation (CNV) has been implicated in cases of early onset obesity that may be comorbid with intellectual disability. Here, we describe a recurrent CNV that causes a syndrome associated with intellectual disability, seizures, macrocephaly, and obesity. This unbalanced chromosome translocation leads to duplication of over 100 genes on chromosome 12, including the obesity candidate gene G protein β3 (GNB3). We generated a transgenic mouse model that carries an extra copy of GNB3, weighs significantly more than its wild-type littermates, and has excess intraabdominal fat accumulation. GNB3 is highly expressed in the brain, consistent with G-protein signaling involved in satiety and/or metabolism. These functional data connect GNB3 duplication and overexpression to elevated body mass index and provide evidence for a genetic syndrome caused by a recurrent CNV.

Seizure and EEG patterns in Wolf-Hirschhorn (4p-) syndrome

Wolf-Hirschhorn syndrome (WHS) is a well-characterized chromosomal disorder that occurs due to partial deletion of the short arm of chromosome 4 (4p-). Although, about 300 cases have been reported to date, limited data are available on electroclinical findings. Information given to parents at the time of diagnosis tends to be skewed to the extreme negative. To delineate the natural history of seizures and EEG patterns in WHS, and obtain better information on diagnosis or outcome in a clinical setting, we reviewed the available literature on electroclinical findings of WHS. 4p- syndrome is characterized by distinctive seizure and EEG patterns that facilitate the early diagnosis and management of such patients.

Wolf-Hirschhorn syndrome--two case-study reports focusing particularly on long-term survival

BACKGROUND

The clinical features of this rare chromosomal syndrome are described in two individuals. Our limited knowledge of the natural history of this disorder has made it difficult to counsel parents as well as outline specific treatment and management plans.

METHOD

Interviews were undertaken with subjects, carers and next of kin, and the literature was searched.

RESULTS

Pertinent features of the syndrome are reported.

MAIN CONCLUSIONS

These two cases highlight that long-term survival may occur and that accurate diagnosis is paramount so that healthcare professionals are able to provide accurate information.

Histopathological basis of hearing impairment in Wolf-Hirschhorn syndrome

OBJECTIVES/HYPOTHESIS

To perform histological examination of temporal bones acquired from an infant with Wolf-Hirschhorn syndrome with an emphasis on identifying abnormalities that might be responsible for hearing impairment in this disorder.

STUDY DESIGN

Retrospective case review.

METHODS

Temporal bones were taken at autopsy from a 10-month-old infant with Wolf-Hirschhorn syndrome. The right-side temporal bone was studied by microdissection. The middle ear was examined, and the inner ear sensory organs dissected for study by light microscopy. The left-side temporal bone was embedded in celloidin, and sections were cut for microscopic examination.

RESULTS

Chronic otitis media was observed in both ears. Inflammation, effusion, and adhesions were present in the middle ear space. The malleus was malformed, and the chorda tympani nerve was found to pass through the bone of the malleus bilaterally. There was an area of sharply defined outer hair cell loss in the lower basal turn of the right-side organ of Corti, and defects were noted in the bone of the apical osseous spiral lamina in both cochleae.

CONCLUSION

In addition to the presence of otitis media, the likelihood of congenital abnormalities of the middle and inner ear should be considered in the assessment of patients with Wolf-Hirschhorn syndrome with hearing impairment.

Health supervision and anticipatory guidance of individuals with Wolf-Hirschhorn syndrome

Wolf-Hirschhorn syndrome (WHS) is a well-known malformation syndrome due to microdeletion of the short arm of chromosome 4 (4p-). Almost 120 cases have been reported so far, yet there is still limited information on its natural history. It is generally thought that these children have severe developmental disabilities and tend to be mere survivors devoid of personality. It is evident to us [Battaglia et al., 1999a, 1999b], however, that individuals with WHS are capable of greater psychomotor development than previously suggested [Guthrie et al., 1971]. Thus, it is even more important to establish guidelines for health supervision and anticipatory guidance of such patients. This would help professionals and families in developing the most appropriate individualized plan for each child, in order to allow the maximum achievement possible. In the present article we propose guidelines for health supervision and anticipatory guidance of individuals with WHS. These guidelines derive from our experience with the natural history of several children, adolescents, and adults with WHS, gained through the literature, personal observation, and contacts with the national support groups in North America and Italy.

Natural history of Wolf-Hirschhorn syndrome: experience with 15 cases

Wolf-Hirschhorn syndrome (WHS) is a well-known chromosomal disorder attributable to partial deletion of the short arm of chromosome 4 (4p-). Although about 120 cases have been reported so far, there is still very little data on its natural history. Information given to parents at the time of diagnosis tends to be skewed to the extreme negative. To help delineate more thoroughly the natural history of WHS, and to obtain better information to answer parents' questions in a clinical setting, we evaluated 15 patients (12 females, 3 males) in three centers with the 4p- syndrome. Four of the cases had a follow-up spanning 16 years. Thirteen cases were detected by standard cytogenetics (regular G-banding 10, high-resolution banding 3), while the remaining 2 required fluorescence in situ hybridization. A total of 5/15 (33.3%) had heart lesions; 7/15 (46. 6%) had oral facial clefts; 13/15 (86.6%) had a seizure disorder, that tended to disappear with age; and 100% had severe/profound developmental retardation. One Italian patient had sensorineural deafness and 1 Utah patient had a right split hand defect. Of note, 2 Utah patients were able to walk with support (at 4 and 12 years of age, respectively), whereas 3 Italian patients and 1 Utah patient were able to walk unassisted (at 4, 5, 5 years 9 months, and 7 years of age, respectively). Two of the 3 Italian patients also achieved sphincter control (by day). The 8 patients receiving serial electroencephalogram studies showed fairly distinctive abnormalities, usually outlasting seizures. A slow, but constant progress in development was observed in all cases, during the follow-up period. In conclusion, the combined cases of the three centers represent considerable experience, providing new information on several aspects of this important deletion syndrome.

Translocations involving 4p16.3 in three families: deletion causing the Pitt-Rogers-Danks syndrome and duplication resulting in a new overgrowth syndrome

Three families are reported who have a translocation involving 4p16.3. Nine subjects are described with the clinical features of the Pitt-Rogers-Danks (PRD) syndrome confirming pre- and postnatal growth failure, microcephaly, severe mental retardation, seizures, and a distinctive facial appearance; a deletion of 4p16.3 was seen in all eight patients studied with fluorescence in situ hybridisation (FISH). Eleven subjects had a new syndrome with physical overgrowth, heavy facial features, and mild to moderate mental handicap; a duplication of the chromosome region 4p16.3 was found in the four subjects studied. It is suggested that the growth abnormalities in these two families may be explained by a dosage effect of the fibroblast growth factor receptor gene 3 (FGFR3), which is located at 4p16.3, that is, a single dose leads to growth failure and a triple dose to physical overgrowth. We describe the molecular mapping of the translocation breakpoint and define it to within locus D4S43.

The Wolf-Hirschhorn syndrome in adulthood: evaluation of a 24-year-old man with a rec(4) chromosome

We described a profoundly intellectually disabled 24-year-old man with Wolf-Hirschhorn syndrome, left hemiplegia, epilepsy, atrophy of the right cerebral hemisphere, and dilatation of the right ventricle. The patient had a small ventricular septal defect, was wheelchair bound, and totally dependent. He had no speech, but vocalised to show his feelings. In this patient, the del(4)(p15) was subtle and arose due to the inheritance of a recombinant chromosome (4) from a maternal pericentric inversion-46,XX,inv(4) (p15.32q35). Fluorescence in situ hybridisation with probe D4S96 confirmed the deletion. This is the second case of Wolf-Hirschhorn syndrome resulting from a large pericentric inversion of chromosome 4.

Microdissection and DOP-PCR-based reverse chromosome painting as a fast and reliable strategy in the analysis of various structural chromosome abnormalities

Reverse chromosome painting has become a powerful tool in clinical genetics for the characterization of cytogenetically unclassifiable aberrations. In this report, the application of a sensitive and rapid procedure for the complete and precise identification of four different de novo structural chromosome abnormalities is presented. These chromosome rearrangements include a marker derived from chromosome 3(cen-q11), an interstitial deletion of chromosome 13 [del(13)(q14q22)], an unbalanced translocation [46,XY, -4, +der(4)t(4;8)(p 15.2;p21.1)] leading to Wolf-Hirschhorn syndrome, and a partial inverted duplication in conjunction with a partial deletion of chromosome 5p [46,XX, -5, +der(5)(:p13-p15.1::p15.1-qter)] which is responsible for the manifestation of the cri-du-chat syndrome. The importance of a fast and reliable evaluation of complex chromosome aberrations in pre- and postnatal diagnosis with regard to comprehensive genetic counselling is emphasized.