45, X-46, XY chromosome mosaic with features of the Russell-Silver syndrome: a case report with a review of the literature

Chromosomal rearrangements in patients with clinical features of Silver-Russell syndrome

Silver-Russell syndrome (SRS) is characterized by pre- and postnatal growth retardation, relative macrocephaly, asymmetry, and a triangular facial gestalt. In 5-10% of the patients the phenotype is caused by maternal UPD 7, and 38-64% of the patients present with hypomethylation at the imprinting center region 1 (ICR1) on 11p15.5. The etiology of the remaining cases is so far not known and various (sub-)microscopic chromosome aberrations with a phenotype resembling SRS have been published, especially duplication 11p15 (n = 15), deletion 12q14 (n = 19), ring chromosome 15, deletion 15qter, and various other mostly unique chromosomal aberrations (n = 30). In this study the phenotypes of these chromosomal aberrations were revisited and compared with the phenotypes of maternal UPD 7 and hypomethylation at ICR1 on 11p15.5. In some patients with a unique chromosomal aberration even the hallmarks of SRS were missing. Patients with duplication 11p15 show a more variable occipitofrontal head circumference at birth, a higher frequency of intellectual disability, and additional anomalies not reported in SRS. Deletion 12q14 is characterized by less severe pre- and postnatal growth retardation and less impressive relative macrocephaly. Patients with ring chromosome 15 and deletion 15qter have no relative macrocephaly (mostly even microcephaly) and more severe intellectual disability. Finally, deletion 15qter lacks the triangular facial gestalt. In summary, as SRS seems not an adequate diagnosis in many of these patients, diagnosis should focus on the chromosomal aberration than on SRS.

Growth and symptoms in Silver-Russell syndrome: review on the basis of 386 patients

The spontaneous growth of 386 patients (163 girls and 223 boys) with Silver-Russell syndrome (SRS) was analysed in a mixed longitudinal and cross-sectional manner. One hundred and twenty patients were seen in the two centres between 1970 and 1993, additional definite cases were added from the literature. Mean (+/- SD) length of full-term babies with SRS at birth was 43.1 +/- 3.7 cm (n = 102) in both sexes. Mean weight at birth was 1940 +/- 353 g in boys and 1897 +/- 325 g in girls. During the first 3 years of life there was poor growth with a further loss in height. Between ages 4 and 10 years there was constant growth in parallel to the 3rd percentile with a mean height SDS of -4.3. The pubertal growth spurt was reduced in the whole group. Bone age development paralleled growth, retardation increased during the first years, remained constant during prepubertal time and caught up in early puberty. Mean adult height was 151.2 +/- 7.8 cm in males and 139.9 +/- 9.0 cm in females. Head circumference for age was in the lower normal range (mean SDS for 156 prepubertal boys -1.8; mean SDS for 97 prepubertal girls -2.2).

CONCLUSION

Normative data on spontaneous growth of children with Silver-Russell syndrome are described, allowing a better counselling of patients as well as the judgement of the effects of growth promoting therapies.

Dup(1q)(q42-->qter) syndrome: case report and review of literature

We report on a patient with primordial growth retardation, mental retardation, and minor anomalies (triangular face, open sagittal suture, frontal bossing, telecanthus, upturned nose, micrognathia, and small mouth with downturned corners). The diagnosis of Russell-Silver syndrome (RSS) had been considered but was abandoned when cytogenetic evaluation showed a partial trisomy 1q or duplication 1q (46,XY,15, + der(15)t(1;15)(q42;qter). Data from another 5 reports of dup(1)(q42-->qter) do not allow delineation of a typical syndrome. However, individuals with dup(1q), del(15q), and Russell-Silver syndrome share common manifestations (i.e., low birth weight, growth retardation, triangular face, low set/abnormal ears, micrognathia, renal anomalies.

Silver-like syndrome and a small deletion on chromosome 13

A female child is described with features of Silver's syndrome, including pre- and postnatal growth delay, triangular face, hypertelorism, clinodactyly and developmental delay. In all lymphocytes analyzed, a small deletion was found in chromosome 13. The karyotype was 46,XX,del(13)(q22-32).

Russell-Silver syndrome

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45,X/46,XY mosaicism: contrast of prenatal and postnatal diagnosis

The process of prenatal diagnosis is unique in that the diagnosis and prognosis are made without seeing the patient. 45,X/46,XY mosaicism presents a special problem in this regard. The phenotype of 45,X/46,XY postnatally diagnosed children (pediatric group) was compared to that of 6 fetuses who were diagnosed from 7,000 amniocenteses (prenatal group). These amniocenteses were performed primarily because of an increased risk of chromosome abnormality. The pediatric group (age birth-18 yr) were all phenotypically abnormal, although none were mentally retarded. Seven patients presented with ambiguous genitalia, while 2 had primary amenorrhea. Sexual assignment was changed in 2. Abnormalities included rudimentary phallus, urogenital sinus, hypospadias, undescended testes, and short stature. All 9 patients required at least one surgical procedure. In contrast, the prenatally diagnosed fetuses (ages 3 months to 3 1/2 yr) were all phenotypically normal males. Four were noted to have male genitalia on ultrasonography. Thus, the phenotype of 45,X/46,XY mosaicism in prenatally diagnosed fetuses can be markedly different from that of individuals diagnosed postnatally. This must be considered when counseling patients.

Reevaluation of Russell-Silver syndrome

Russell-Silver syndrome was reevaluated 2.9 to 13.0 years after initial diagnosis in 15 patients. At follow-up, five of the 15 patients exhibited late catch-up growth and had normal height, six had developmental delays or mental retardation, and asymmetry was present in five. Given the great variability in the long-term prognosis for growth and development in patients with Russell-Silver syndrome, there is a need to reevaluate this syndrome and its clinical implications.

Congenital hypoplastic thumb in the Silver syndrome--a case report and review of upper extremity anomalies in the world literature

A case of classical Silver syndrome presented with a congenital hypoplastic thumb, absent thenar musculature, and partial index ankylosis. No previous association of congenital hypoplastic thumb and the Silver syndrome has been noted by Dr. Silver or described in the world literature. Restoration of thumb function was achieved in this particular case by the abductor digiti minimi transfer described by Huber. The upper extremity anomalies thus far reported with Silver syndrome in the world literature are summarized.

Phenotypic and genetic analysis of the silver-Russell syndrome

A family is reported in which two half-siblings present clinical findings suggestive of the Silver-Russell syndrome (SRS). The available published literature on SRS is reviewed and the variable expression of the syndrome demonstrated. A review of published pedigrees of the syndrome suggests that in a small percentage of cases, SRS has a genetic etiology.

Deletion short arm 18 and Silver-Russell syndrome

A 14-year-old boy presented with physical signs of the Silver-Russell syndrome. He further had low-set, large protruding ears, ptosis, broad nasal base, thick protruding lips, pronounced caried, malaligment of teeth, micrognathia and mental retardation. Chromosome examination showed deletion of the short arms of chromosome No. 18. It is concluded that considering the previous findings of chromosome No. 18 aberrations in some patients with Silver-Russell syndrome such patients should always have chromosome examination made.

Follow-up till age 3--4 of unselected children with sex chromosome abnormalities

Follow-up examination of 15 unselected children with aneuploid sex chromosome abnormalities has been made till between the age of 2 1/2 and 5 years. The mental development of the 15 children was in all cases within the normal range, but there was a tendency to some differences compared with their siblings.

Trisomy-18 mosaicism with features of Russel-Silver syndrome

A child is described who presented at 16 months with developmental delay and clinical features of the Russell-Silver syndrome. Chromosome analysis revealed trisomy-18 mosaicism. Only one other similar case has been reported in the literature. It is recommended that chromosomal studies continue to be included in the clinical investigation of children with Russell-Silver syndrome.