Prenatal diagnosis of Seckel syndrome at 21 weeks' gestation and review of the literature

Small size, big problems: insights and difficulties in prenatal diagnosis of fetal microcephaly

Microcephaly is a sign, not a diagnosis. Its incidence varies widely due to the differences in the definition and the population being studied. It is strongly related to neurodevelopmental disorders. Differences in definitions and measurement techniques between fetuses and newborns pose a great challenge for the diagnosis and prognostication of fetal microcephaly. A false positive diagnosis can result (in countries where it is legal) in erroneous termination of pregnancy, where a false negative diagnosis might lead to the birth of a microcephalic newborn. Microcephaly in growth restricted fetuses deserves special attention and separate evaluation as it is an important prognostic factor, and not necessarily part of the general growth retardation. Several genetic syndromes incorporating microcephaly and intrauterine growth retardation (IUGR) are discussed. Deceleration of the head circumference (HC) growth rate even when the HC is still within normal limits might be the only clue for developing microcephaly and should be considered during fetal head growth follow up. Combining additional parameters such as a positive family history, associated anomalies, and new measurement parameters can improve prediction in about 50% of cases, and thus should be part of the prenatal workup. Advances in imaging modalities and in prenatal genetic investigation along with the emergence of new growth charts can also improve diagnostic accuracy. In this article, we review the different definitions and etiologies of fetal microcephaly, discuss difficulties in diagnosis, investigate the reasons for the low yield of prenatal diagnosis, and provide improvement suggestions. Finally, we suggest an updated algorithm that will aid in the diagnosis and management of fetal microcephaly.

Two novel variants in CEP152 caused Seckel syndrome 5 in a Chinese family

Background: Seckel syndrome (SCKL) is a rare autosomal recessive inherited disorder, which is mainly characterized by intrauterine and postnatal growth restrictions, microcephaly, intellectual disability, and a typical "bird-head" facial appearance. Here, we aimed to identify the genetic etiology of a family with suspected SCKL. Methods: This study enrolled a Chinese family suspected of SCKL with their detailed family history and clinical data. We performed karyotype analysis, copy number variation sequencing (CNV-seq), and trio whole-exome sequencing (WES) to explore the genetic etiology in the proband. Furthermore, the quantitative real-time polymerase chain reaction (PCR) and reverse transcription-PCR (RT-PCR) were conducted to confirm the pathogenicity of novel variants. Results: The karyotype analysis and CNV-seq were normal in the proband. Two novel variants in CEP152, c.1060C>T (p.Arg354*) and c.1414-14A>G, were identified in the proband through trio-WES. The qPCR results showed that the total CEP152 mRNA expression levels were significantly reduced in c.1060C>T (p.Arg354*) and c.1414-14A>G compared with healthy control individuals. Moreover, aberrant skipping of exon 12 due to the non-canonical splice-site variant was revealed by RT-PCR and Sanger sequencing. Conclusion: Our findings expanded pathogenic variant spectra in SCKL and offered new insights into the pathogenicity of a non-classical splice-site variant in CEP152, which provided additional information for helping the family improve pregnancy plans in the future.

Prenatal ultrasound diagnosis of Seckel syndrome with bi-allelic variant in TRAIP via exome sequencing

We present two consecutive pregnancies with shared ultrasound findings-sloping forehead, micrognathia, ambiguous genitalia, brachycephaly, short extremities, single umbilical artery, choroid plexus cysts, and clenched hands. Subsequent whole exome sequencing identified TRAIP gene variants implicating diagnosis of Seckel syndrome 9 (SCKL9). Prenatal testing in subsequent pregnancy identified one variant. Our case highlights the utility of whole exome sequencing when prenatal ultrasound findings lend suspicion. Molecular confirmation allows for testing strategies in, or prior to, subsequent pregnancies. The finding of a rare, novel missense variant in TRAIP gene further implicates this mutation as having deleterious clinical manifestations.

A Child with Seckel Syndrome and Arterial Stenosis: Case Report and Literature Review

Background

Seckel syndrome is a rare genetic disorder with autosomal recessive inheritance. It is characterized by dysmorphic features, intrauterine and postnatal growth restriction, microcephaly and mental retardation. Although cardiovascular complications are not prevalent in this syndrome, severe sinus bradycardia, hypertension and brain vasculopathy are reported. Here, for the first time, we describe a case of lower extremity arterial occlusion in a case of Seckel syndrome.

Case Presentation

An 8-year-old girl with the characteristic features of Seckel syndrome was admitted to the children's hospital with the complaint of left lower extremity pain and a deep ulcer on her left shin. On examination, the left extremity was cooler than the other side, with a bluish color. Dorsalis pedis and popliteal artery pulses were not palpable on the left. A wound measuring 3 by 5 cm with gangrenous margins was visible on the anterior surface of the left leg. Severe stenosis in the left superficial femoral artery was reported on angiography. Considering the lean body of the patient, angioplasty was not possible and conservative wound care, analgesic drugs and aspirin were recommended.

Conclusion

Clinicians should be suspicious of vascular complications in patients with Seckel syndrome, even in the absence of any other risk factors.

The Seckel syndrome: A case observed in the pediatric department of the University Hospital Center Sourou Sanou (Burkina Faso)

Seckel syndrome-1 or "bird-headed dwarfism", Online Mendelian Inheritance in Man number 210600, is a rare genetic disease with an autosomal recessive transmission. We report a female child of 56 months diagnosed with SCKL1 at the Pediatric department of the University Hospital Center Sourou Sanou, Burkina Faso. She showed the typical features including facial dysmorphism, dwarfism, microcephalus and mental retardation. Ophthalmic and dental anomaly and extremities were associated. Without a codified etiological treatment, a psychotherapist support, a genetic counseling, a regular pediatric follow-up, a quarterly odontostomatological and ophthalmological follow- up have been recommended.