Fraser syndrome without cryptophthalmos: Two cases

A multidisciplinary approach for prenatal diagnosis of FRASER SYNDROME-report of a novel variant in FRAS1

OBJECTIVE

With this case report, we would like to highlight the importance of a multidisciplinary approach and atypical findings of congenital high airway obstruction sequence (CHAOS), anhydramnios, and renal dysgenesis in the prenatal diagnosis of Fraser syndrome (FS).

CASE REPORT

A 25-year-old primigravida at 19 weeks of routine anomaly scan revealed abnormal sonographic findings such as fetal bilateral dysplastic small kidneys and gross oligohydramnios. The further detailed evaluation revealed that both fetal lungs were hyperechogenic with prominent (dilated) trachea and bronchi suggestive of CHAOS. Based on these findings, a diagnosis of FS was suspected. The couple was counseled and the pregnancy was terminated. The postmortem evaluation and novel homozygous variant in the FRAS1 gene confirmed the diagnosis of FS.

CONCLUSION

The diagnosis and counseling of the patient were supported by a well-coordinated, multidisciplinary approach involving an obstetrician, a fetal medicine specialist, a medical geneticist, and a fetal pathologist.

Excluding embryos with two novel mutations in FREM2 gene by the next-generation sequencing-based single nucleotide polymorphism haplotyping

Fraser syndrome is a rare autosomal recessive malformation disorder. It is characterized by cryptophthalmos, syndactyly, urinary tract abnormalities and ambiguous genitalia. This condition is due to homozygous or heterozygous mutations in the FRAS1, FREM1, FREM2, and GRIP1 genes. In the present study, we recruited a Chinese family with Fraser syndrome. Two novel mutations c.7542_7543insG and c.2689C>T in the FREM2 gene were detected in this Fraser syndrome family by PCR-based sequencing. The next-generation sequencing-based single nucleotide polymorphism haplotyping method was applied to exclude these two mutations in 9 blastocysts obtained from the patient. After obtaining consent and informing the risk, the patient received in vitro fertilization and embryo transfer treatment with an embryo carrying a heterozygous mutation. Finally, she delivered a healthy baby without any complications on March 17, 2019. In conclusion, we first reported two novel mutations in the FREM2 gene associated with the risk of Fraser syndrome. Moreover, we described a next-generation sequencing-based single nucleotide polymorphism haplotyping method to select the ‘right’ embryos from patients with Fraser syndrome for in vitro fertilization and embryo transfer treatment.

Updates on congenital lacrimal drainage anomalies and their association with syndromes and systemic disorders: A major review

BACKGROUND

To review and update the syndromic and non-syndromic systemic associations of congenital lacrimal drainage anomalies.

METHODS

The authors performed a PubMed search of all articles published in English on congenital lacrimal drainage anomalies (CLDA). The current review provides an update from January 2017 to August 2020 on all CLDA associated with clinical syndromes or non-syndromic systemic disorders. The update intends to appraise the readers on all papers that were published in the interim 3-year period since the publication of the previous major review by authors (1933-2016). Patients with specific syndromes or systemic disorders were then reviewed. Pertinent cross-references from each of the short-listed articles were also included. Data reviewed include syndromic descriptions, systemic details, demographics, lacrimal presentations, management, and outcomes.

RESULTS

There have been significant new updates. Eleven new syndromes have been added to the list of syndromic associations, of which three were suspects. Among the new syndromic associations, three (PHACE, Williams-Beuren, and Peter's plus syndromes) described CLDA details in depth. Several new non-syndromic systemic conditions with associated CLDA also came to light, the foremost amongst them being proboscis lateralis, diprosopus dirrhinus, cerebral palsy, and NGLY-1 related disorders. Although familial presentations have been reported, the inheritance patterns are unclear for most anomalies. Surgical challenges in these patients are distinct, and a thorough pre-operative assessment, including detailed imaging when indicated, may facilitate good outcomes. Two updated tables reflecting the summary of syndromic and non-syndromic systemic associations are provided to capture the details at a glance.

CONCLUSION

It is not very uncommon to find CLDA in syndromic or non-syndromic systemic disorders. Diagnosis of a craniofacial syndrome should prompt the physician to look out for CLDA. Similarly, a diagnosis of multiple CLDA should alert the examiner for the possible presence of associated systemic anomalies.