Pelle Sahlin

Auditory ERPs reveal brain dysfunction in infants with plagiocephaly.

It is suspected that the developmental delay in school-aged children diagnosed as infants suffering from plagiocephaly is caused by the modification of the skull form. To detect possible cognitive impairment in these children, we examined auditory ERPs to tones in infant patients. The infants with plagiocephaly exhibited smaller amplitudes of the P150 and the N250 responses to tones than healthy controls. Differences between the patients and control subjects indicate that already at this early age the presence of the plagiocephalic skull signals compromise of brain functioning. The present data suggest that most of the plagiocephalic infants have an elevated risk of auditory processing disorders. In the current study we demonstrated, for the first time, that the central sound processing, as reflected by ERPs, is affected in children with plagiocephaly.

Spring-assisted cranioplasty vs pi-plasty for sagittal synostosis--a long term follow-up study.

Spring-assisted cranioplasty (SAS) has been used for the treatment of selected cases of sagittal synostosis at our unit routinely since 1998. In order to assess the long-term outcomes of this procedure, we compared the clinical data and morbidity with the pi-plasty technique, our previous standard procedure for the treatment of such children. The first 20 consecutive patients who underwent SAS for isolated sagittal synostosis with complete records, and who were 3 years old at the time of this study, were included. Twenty patients with a pi-plasty performed in the period immediately preceding the spring group acted as a control group. Cephalograms (preoperative, 1-year and 3-year), clinical examination, medical record data, medical photography, and a questionnaire (spring-group only) were used to evaluate and compare these two groups. The mean age of the spring group was 3.5 months (2.5-5.5) and the pi-plasty group 7.1 months (4-15.5) of age at surgery. There were no deaths in either group. There was a higher rate of complications in the pi-plasty group. The skull morphology was similar preoperatively in both groups but slightly different at the 3-year follow-up. The mean cephalic index (CI) in the spring group was 72 at 1 year of age and 71 at 3 years of age, indicating a minor relapse. The pi-plasty group had a mean CI of 73 at 3 years of age. The length was the same in both groups however the pi-plasty group had a lower height (mean 2 mm) and wider biparietal distance (mean 5 mm). All parents of the spring group were highly satisfied with the aesthetic results achieved, would undergo the operation again, and would recommend it to others with scaphocephaly. It was concluded that the two groups of surgery resulted in a quite similar morphologic outcome. The pi-plasty group had a cephalic index marginally closer to the normal range at 3 years of age. The spring group was superior with respect to blood loss, transfusion requirements, operative time, ICU time, recovery time, and total hospital stay.

Mental Development After Modified π Procedure: Dynamic Cranioplasty for Sagittal Synostosis

A prospective developmental assessment was performed on 26 patients operated on with dynamic cranioplasty for sagittal synostosis. Because this technique entails the application of compressive force, it was of great concern to assess the effect of surgery on development and mental status. The surgical technique used was a modified &pgr; procedure. Perioperative variables were recorded. Six patients underwent preoperative intracranial pressure (ICP) measurements. To evaluate objectively the developmental outcome, the Griffiths’ Mental Development Scales was used for analysis before and after surgery. A parental questionnaire was used for subjective outcome measurement. Preoperative ICP recordings during sleep ranged from 12.8 to 22.8 mmHg (mean, 16.1 mmHg). The mean age at the time for surgery was 6.9 months (range, 4–16 months; standard deviation [SD], 2.32 months). The surgical technique included shortening of the anteroposterior diameter of the skull by a mean of 16.6 mm. The mean global development quotient (GDQ) preoperatively was 104.5 (range, 82–144; SD, 12.4) and the mean GDQ postoperatively was 101.4 (range, 62–129; SD, 13.6). Mean age at follow-up was 16.3 months (range, 9–40 months; SD, 4.04 months). There was no significant correlation between the amount of intraoperative shortening and mental development. In comparison of means, the GDQ preoperatively did not differ significantly from the GDQ postoperatively. The modified &pgr; procedure is safe and efficient. When surgery was performed before 1 year of age, no significant (p = 0.33) effect on mental development-either detrimental or beneficial-was demonstrated.

Women with Saethre-Chotzen syndrome are at increased risk of breast cancer

The Saethre‐Chotzen syndrome is an autosomal, dominantly inherited craniosynostosis caused by mutations in the basic helix‐loop‐helix transcription factor gene TWIST1. This syndrome has hitherto not been associated with an increased risk of cancer. However, recent studies, using a murine breast tumor model, have shown that Twist may act as a key regulator of metastasis and that the gene is overexpressed in subsets of sporadic human breast cancers. Here, we report a novel association between the Saethre‐Chotzen syndrome and breast cancer. In 15 Swedish Saethre‐Chotzen families, 15 of 29 (52%) women carriers over the age of 25 had developed breast cancer. At least four patients developed breast cancer before 40 years of age, and five between 40 and 50 years of age. The observed cases with breast cancer (n = 15) are significantly higher than expected (n = 0.89), which gives a standardized incidence ratio (SIR) of 16.80 (95% CI 1.54–32.06). Our finding of a high frequency of breast cancer in women with the Saethre‐Chotzen syndrome identifies breast cancer as an important and previously unrecognized symptom characteristic of this syndrome. The results strongly suggest that women carriers of this syndrome would benefit from genetic counseling and enrolment in surveillance programs including yearly mammography. Our results also indicate that the TWIST1 gene may be a novel breast cancer susceptibility gene. Additional studies are, however, necessary to reveal the mechanism by which TWIST1 may predispose to early onset breast cancer in Saethre‐Chotzen patients.

Orbital fractures in craniofacial trauma in Göteborg: trauma scoring, operative techniques, and outcome

In the 10-year period 1986-1996, 85 patients were admitted to our unit with craniofacial injuries, 56 of whom had orbital fractures. These were studied with respect to the type of injury, type and location of fracture, presence of ocular and intracranial injury, and associated injuries to the head and body, as well as operative techniques used. Both the patients and the surgeons opinion on the aesthetic result were noted. The patients were also given a questionnaire about their quality of life after the injury. Road traffic crashes accounted for 31 (55%) of the injuries, falls for 9 (15%), and horse-riding for 6 (11%). The Injury Severity Score (ISS) ranged from 4 to 41 (mean 18). Twelve also had eye injuries, which resulted in complete blindness in one eye in 4 (7%). Thirty patients had 41 neurological injuries (54%), frontal contusions being the most frequent diagnosis ( n r = r 15). Exact repositioning with rigid fixation included bone grafting to the orbit in 11 patients, and the dominating bone graft was split calvarium ( n r = r 5). Forty-two patients completed a questionnaire, 26 of whom (64%) had no aesthetic complaints. Seven of the 42 were too disabled to work one year after the injury. Re-exploration was infrequent and the aesthetic outcome, both in the surgeons and the patients opinion, was good. However, the older the patient, the worse the outcome.

Germline mutation in the FGFR3 gene in a TWIST1-negative family with Saethre-Chotzen syndrome and breast cancer.

In a recent study published in Genes Chromosomes and Cancer (Sahlin et al., 2007), we showed that women with the Saethre-Chotzen syndrome, caused by mutations in the basic helix-loop-helix transcription factor gene TWIST1 (El Ghouzzi et al., 1997; Howard et al., 1997), have an increased risk of breast cancer. In 15 Saethre-Chotzen families, we found that >50% of female carriers older than 25 had developed breast cancer. These findings identified breast cancer as an important and previously unrecognized symptom typical of this syndrome and indicated that TWIST1 may be a novel breast cancer susceptibility gene. Saethre-Chotzen syndrome is one of the most common craniosynostosis (premature fusion of one or more cranial sutures) syndromes characterized by coronal synostosis, S-shaped blepharoptosis, low set ears with typical apical cartilage deformity, cutaneous syndactyly of dig II-III, typical nasal deformity, and low frontolateral hairline (references in Pantke et al., 1975; Sahlin et al., 1994, 2007). It is an autosomal dominantly inherited syndrome with a variable expressivity (Pantke et al., 1975; Reardon and Winter, 1994). Genetic analyses of both familial and sporadic cases have shown that Saethre-Chotzen is genetically heterogeneous (Paznekas et al., 1998; Chun et al., 2002). The majority of cases are caused by mutations in TWIST1 but there are also welldocumented cases caused by mutations in the FGFR2 or FGFR3 genes. Approximately 80% of patients with a Saethre-Chotzen phenotype have mutations in one of these three genes (Chun et al., 2002). As part of our continued studies of SaethreChotzen syndrome and its recently established association with breast cancer, we have now identified and characterized a TWIST1-negative family with a Saethre-Chotzen phenotype and breast cancer (Family 7 in Sahlin et al., 2007). A 61-year-old woman (designated mother), whose father also had Saethre-Chotzen syndrome, presented with typical clinical signs of Saethre-Chotzen, including unicoronal synostosis, symmetrical cutaneous syndactylies of the hands and feet (dig II-III), low set ears with typical apical cartilage deformity, and hearing impairment. At the age of 55, she developed breast cancer. Six years after surgery, she is alive and well. Nucleotide sequence analysis of DNA isolated from a blood sample revealed no mutation of the TWIST1 gene (data not shown). As Saethre-Chotzen syndrome may also be caused by mutations in the FGFR2 and FGFR3 genes (see earlier), we also screened these genes for possible mutations. All exons of the FGFR2 (19 exons) and FGFR3 (19 exons) genes were sequenced using bidirectional DNA sequencing essentially as described earlier (Persson et al., 2008; PCR primers for DNA sequencing are available on request). Briefly, sequence PCR was performed using the BigDye Terminator v3.1 Cycle Sequence Kit (Applied Biosystems, Foster City, CA). The sequencing products were separated with gel electrophoresis on a 3730 DNA analyser (Applied Biosystems) and the output data were analyzed using SeqScape v 2.5 (Applied Biosystems). Analysis of the resulting sequences revealed a mutation in FGFR3 exon 7, i.e., 749C>G (Pro250Arg; P250R), in the DNA of the mother (Fig. 1). This missense mutation was present in a heterozygous state. Furthermore, multiplex ligation-dependent probe amplification (MLPA) analysis was performed using the Salsa MLPA Kit P080 (MRC-Holland, The Netherlands), as described by the manufacturer. This kit is developed for detection of large deletions in a set of genes known to be involved in craniofacial disorders (ALX4, TWIST1, RUNX2, MSX2, FGFR1/2/3/4, and EFNB1). A probe for FGFR3 exon 7 gave a signal of half the intensity for the DNA of the mother as compared to healthy control DNA (Fig. 1). It is described by the manufacturer of the MLPA kit (MRC-Holland) that

Cytogenetic and fluorescence in situ hybridization analyses of a microcystic adnexal carcinoma with del(6)(q23q25)

Cytogenetic analysis of a case of microcystic adnexal carcinoma (MAC) revealed three unrelated clones with the karyotypes: 46,XX,del(6)(q23q25)[17]/46,XX,1 approximately 2dmin[4]/46,XX,t(1;3) (p10;q10)[2]. Analysis of the 6q- by fluorescence in situ hybridization (FISH) showed that it had resulted from a long arm deletion. The finding of a clonal 6q deletion as the sole karyotypic change in a MAC is of special interest because we previously have identified 6q deletions in different types of malignant salivary gland tumors. This observation, together with the histopathologic similarities between salivary gland tumors and sweat gland tumors, further emphasize the histogenetic relationships between these tumor types.

INT1 and GLI genes are not rearranged or amplified in benign pleomorphic adenomas with chromosome abnormalities of 12q13–15☆

A subgroup of pleomorphic adenomas of the salivary glands is characterized by translocations involving chromosome 12, with consistent breakpoints at 12q13-15. Two proto-oncogenes, INT1 and GLI, have been assigned to this region of chromosome 12. We studied the possible involvement of these genes in pleomorphic adenomas with different karyotypic abnormalities, including cases with involvement of 12q13-15. Using detailed restriction fragment analysis of tumor DNAs from 25 cases, we found no evidence of rearrangement or amplification of INT1 or GLI. Because we previously found an adenoma with a del(12)(q13q15), we also analyzed normal and tumor DNAs from the 25 tumors separately to identify possible allelic losses at the GLI locus. Thirteen of the 25 tumors were informative, and none of these showed evidence of allelic losses. Collectively, these findings indicate that neither the INT1 nor the GLI gene appears to be the primary target gene for the translocations and deletions involving the 12q13-15 region in pleomorphic adenomas.

Reuse of tumorous calvarial bone after gamma irradiation.

Reconstruction of calvarium after tumor resection may present several technical difficulties. The authors reused the resected calvarial bone in four patients after submitting the bone to a lethal dose of gamma radiation. The authors conclude that resected, irradiated, tumorous bone can be reused for the reconstruction of its own defect. This provides a simple method of reconstruction. Partial bone resorption should be anticipated but further reconstruction, if needed, will be facilitated.

Germline mutation screening of the Saethre-Chotzen-associated genes TWIST1 and FGFR3 in families with BRCA1/2-negative breast cancer.

Saethre-Chotzen syndrome is one of the most common craniosynostosis syndromes. It is an autosomal dominantly inherited disorder with variable expression that is caused by germline mutations in the TWIST1 gene or more rarely in the FGFR2 or FGFR3 genes. We have previously reported that patients with Saethre-Chotzen syndrome have an increased risk of developing breast cancer. Here we have analysed a cohort of 26 women with BRCA1/2-negative hereditary breast cancer to study whether a proportion of these families might have mutations in Saethre-Chotzen-associated genes. DNA sequence analysis of TWIST1 showed no pathogenic mutations in the coding sequence in any of the 26 patients. MLPA (multiplex ligation-dependent probe amplification)-analysis also showed no alterations in copy numbers in any of the craniofacial disorder genes MSX2, ALX4, RUNX2, EFNB1, TWIST1, FGFR1, FGFR2,FGFR3, or FGFR4. Taken together, our findings indicate that mutations in Saethre-Chotzen-associated genes are uncommon or absent in BRCA1/2-negative patients with hereditary breast cancer.