Adrenal insufficiency and abnormal genitalia in a 46XX female with Smith-Lemli-Opitz syndrome

Assessing Postnatal Mortality in Smith-Lemli-Opitz Syndrome

Smith-Lemli-Opitz syndrome (SLOS) is a rare autosomal recessive disorder caused by pathological variants in DHCR7, resulting in a deficiency in the enzyme 7-dehydrocholesterol reductase. This results in elevated levels of cholesterol precursors and typically low cholesterol levels, leading to a range of physical and cognitive challenges. Mortality rates in infants with severe SLOS are high, due to congenital malformations. Premature death has been described in individuals with SLOS, particularly in severely affected individuals. Further research is needed to understand postnatal mortality risk factors for individuals with SLOS. Understanding these factors could improve monitoring and prevention efforts. To investigate this, we obtained death certificates from the National Death Index (NDI) database on a cohort of individuals with SLOS who were enrolled in natural history studies at the National Institutes of Health Clinical Center (NCT00001721 and NCT05047354). Analysis and comparison of this deceased cohort showed that although premature death occurs in SLOS, many individuals with SLOS survive into adulthood. We also observed the risk of postnatal mortality increasing with higher severity scores and lower initial cholesterol levels. Trial Registration: NCT00001721 and NCT05047354.

Statins for Smith-Lemli-Opitz syndrome

This is a protocol for a Cochrane Review (Intervention). The objectives are as follows: 1. To evaluate the efficacy of statin therapy in reducing the frequency or severity of the neurobehavioral abnormalities seen in people with SLOS (e.g. aggression, anxiety, irritability, self-mutilation, autistic behaviors, sleep disturbances, etc.) (Wassif 2017). 2. To evaluate the potential effects of statin therapy on survival.

Smith-Lemli-Opitz syndrome: clinical and biochemical correlates

BACKGROUND

Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive disorder caused by mutations in the DHCR7 gene that result in reduced cholesterol biosynthesis. The aim of the study was to examine the biochemical and clinical features of SLOS in the context of the emerging evidence of the importance of cholesterol in morphogenesis and steroidogenesis.

METHODS

We retrospectively reviewed the records of 18 patients (including four fetuses) with confirmed SLOS and documented their clinical and biochemical features.

RESULTS

Seven patients had branchial arch abnormalities, including micrognathia, immune dysfunction and hypocalcemia. Thymic abnormalities were found in three fetuses. All four patients with a cholesterol level of ≤0.35 mmol/L died. They all had electrolyte abnormalities (hyperkalemia, hyponatremia, hypocalcemia), necrotizing enterocolitis, sepsis-like episodes and midline defects including the branchial and cardiac defects. Patients with cholesterol levels ≥1.7 mmol/L had milder features and were diagnosed at 9 months to 25 years of age. All 10 patients had intellectual disability. One patient was found to have a novel mutation, c.1220A>G (p.Asn407Ser).

CONCLUSIONS

We suggest that screening for adrenal insufficiency and for hypoparathyroidism, hypothyroidism and immunodeficiency, should be done routinely in infants diagnosed early with SLOS. Early diagnosis and intervention to correct these biochemical consequences may decrease mortality and improve long-term outcome in these patients.

Pathogenesis, Epidemiology, Diagnosis and Clinical Aspects of Smith-Lemli-Opitz Syndrome

INTRODUCTION

Smith-Lemli-Opitz Syndrome (SLOS) is a malformation syndrome inherited in an autosomal recessive fashion. It is due to a metabolic defect in the conversion of 7-dehydrocholesterol to cholesterol, which leads to an accumulation of 7-dehydrocholesterol and frequently a deficiency of cholesterol. The syndrome is characterized by typical dysmorphic facial features, multiple malformations, and intellectual disability.

AREAS COVERED

In this paper we provide an overview of the clinical phenotype and discuss how the manifestations of the syndrome vary depending on the age of the patients. We then explore the underlying biochemical defect and pathophysiological alterations that may contribute to the many disease manifestations. Subsequently we explore the epidemiology and succinctly discuss population genetics as they relate to SLOS. The next section presents the diagnostic possibilities. Thereafter, the treatment and management as is standard of care are presented.

EXPERT OPINION

Even though the knowledge of the underlying molecular mutations and the biochemical alterations is being rapidly accumulated, there is currently no efficacious therapy addressing neurological dysfunction. We discuss the difficulty of treating this disorder, which manifests as a combination of a malformation syndrome and an inborn error of metabolism. A very important factor in developing new therapies is the need to rigorously establish efficacy in controlled trials.

Brothers with Smith-Lemli-Opitz syndrome

Abnormal cholesterol metabolism is the cause of SLOS, with low cholesterol levels and elevated levels of cholesterol precursors thought to contribute to the clinical findings in this syndrome. Management of SLOS involves early intervention with appropriate therapies for identified disabilities, genetic counseling for families, nutritional consultations, educational interventions, and behavioral management. Although no randomized dietary studies have been conducted, cholesterol supplementation continues to be a common recommendation for persons with SLOS, because it may result in clinical improvement and has few adverse effects (Nowaczyk, 2013). Even with early detection and treatment (e.g., sibling B in this case report), persons with SLOS often have significant behavioral issues and cognitive and developmental delays that require a team approach by parents, educators, specialists, and primary care providers.

Smith-Lemli-Opitz syndrome: phenotype, natural history, and epidemiology

Smith-Lemli-Opitz syndrome (SLOS) is a congenital multiple anomaly/intellectual disability syndrome caused by a deficiency of cholesterol synthesis resulting from a deficiency of 7-dehydrocholesterol (7DHC) reductase encoded by DHCR7. SLOS is inherited in an autosomal recessive pattern. It is characterized by prenatal and postnatal growth retardation, microcephaly, a variable degree of intellectual disability that encompasses normal intelligence to severe intellectual deficiency, and multiple major and minor malformations. External malformations include distinctive facial features, cleft palate, postaxial polydactyly, 2-3 syndactyly of the toes, and underdeveloped external genitalia in males, while internal anomalies may affect every organ system. The clinical spectrum is wide, and rare individuals have been described with normal development and only minor malformations. The clinical diagnosis of SLOS is confirmed by demonstrating an abnormally elevated concentration of the cholesterol precursor, 7DHC, in serum or other tissues, or by the presence of two DHCR7 mutations. The enzymatic deficiency results in decreased cholesterol and increased 7DHC levels, both during embryonic development and after birth. The malformations found in SLOS may result from decreased cholesterol, increased 7DHC or a combination of these two factors. This review discusses the physical and behavioral phenotype of SLOS, the diagnostic approaches, the natural history from the prenatal period to adulthood, and current understanding of the pathophysiology of SLOS.

The molecular profile of microglia under the influence of glioma

Microglia, which contribute substantially to the tumor mass of glioblastoma, have been shown to play an important role in glioma growth and invasion. While a large number of experimental studies on functional attributes of microglia in glioma provide evidence for their tumor-supporting roles, there also exist hints in support of their anti-tumor properties. Microglial activities during glioma progression seem multifaceted. They have been attributed to the receptors expressed on the microglia surface, to glioma-derived molecules that have an effect on microglia, and to the molecules released by microglia in response to their environment under glioma control, which can have autocrine effects. In this paper, the microglia and glioma literature is reviewed. We provide a synopsis of the molecular profile of microglia under the influence of glioma in order to help establish a rational basis for their potential therapeutic use. The ability of microglia precursors to cross the blood-brain barrier makes them an attractive target for the development of novel cell-based treatments of malignant glioma.

Adrenal function in Smith-Lemli-Opitz syndrome

Smith-Lemli-Opitz syndrome (SLOS) is a multiple malformation syndrome due to mutations of the 7-dehydrocholesterol reductase gene (DHCR7), which leads to a deficiency of cholesterol synthesis and an accumulation of 7-dehydrocholesterol. The SLOS clinical spectrum ranges from multiple major malformations to a mild phenotype with minor anomalies and intellectual disability. Several children with SLOS and adrenal insufficiency have been described. We performed ovine corticotropin (oCRH) testing in 35 SLOS patients and 16 age- and gender-matched controls. We reviewed prior adrenocorticotropin (ACTH) stimulation tests of our SLOS patients (19 of 35 available) and reviewed results of ACTH stimulation tests from 10 additional SLOS patients. Results from oCRH testing showed that patients with SLOS had significantly higher ACTH baseline values than healthy controls (24.8 ± 15.3 pg/ml vs. 17.8 ± 7.5 pg/ml, P = 0.034). However, no statistically significant differences were noted for peak ACTH values (74.4 ± 35.0 pg/ml vs. 64.0 ± 24.9 pg/ml, P = 0.303) and for baseline (14.2 ± 7.8 mcg/dl vs. 14.2 ± 6.3 mcg/dl, P = 0.992) and peak cortisol values (28.2 ± 7.9 mcg/dl vs. 24.8 ± 8.1 mcg/dl, P = 0.156). The area-under-the-curve (AUC) was not significantly different in SLOS patients compared to controls for both ACTH (250.1 ± 118.7 pg/ml vs. 195.3 ± 96.6 pg/ml, P = 0.121) as well as cortisol secretion (83.1 ± 26.1 mcg/dl vs. 77.8 ± 25.9 mcg/dl, P = 0.499). ACTH stimulation test results were normal in 28 of 29 tests. The individual with the abnormal test results had subsequent normal oCRH tests. The slightly increased baseline ACTH level seen during oCRH testing may be due to compensated adrenocortical insufficiency. However, we were able to show that our patients with SLOS had an adequate glucocorticoid response, and thus, in mild to moderate cases of SLOS stress steroid coverage may not be warranted.

In search of adrenocortical stem and progenitor cells

Scientists have long hypothesized the existence of tissue-specific (somatic) stem cells and have searched for their location in different organs. The theory that adrenocortical organ homeostasis is maintained by undifferentiated stem or progenitor cells can be traced back nearly a century. Similar to other organ systems, it is widely believed that these rare cells of the adrenal cortex remain relatively undifferentiated and quiescent until needed to replenish the organ, at which time they undergo proliferation and terminal differentiation. Historical studies examining cell cycle activation by label retention assays and regenerative potential by organ transplantation experiments suggested that the adrenocortical progenitors reside in the outer periphery of the adrenal gland. Over the past decade, the Hammer laboratory, building on this hypothesis and these observations, has endeavored to understand the mechanisms of adrenocortical development and organ maintenance. In this review, we summarize the current knowledge of adrenal organogenesis. We present evidence for the existence and location of adrenocortical stem/progenitor cells and their potential contribution to adrenocortical carcinomas. Data described herein come primarily from studies conducted in the Hammer laboratory with incorporation of important related studies from other investigators. Together, the work provides a framework for the emerging somatic stem cell field as it relates to the adrenal gland.