Preferred Label : Smith-lemli-opitz syndrome;
Symbol : SLOS;
CISMeF acronym : SLOS;
Type : Phenotype, molecular basis known;
Alternative titles and symbols : Slo syndrome; Rsh syndrome; Lethal acrodysgenital syndrome; Rutledge lethal multiple congenital anomaly syndrome; Polydactyly, sex reversal, renal hypoplasia, and unilobar lung;
Description : Smith-Lemli-Opitz syndrome is an autosomal recessive multiple congenital malformation
and mental retardation syndrome. Although historically a clinical distinction was
often made between a classic 'type I' disorder and a more severe 'type II' disorder,
in reality the syndrome constitutes a clinical and biochemical continuum from mild
to severe (Opitz et al., 1987; Cunniff et al., 1997; Kelley, 1998). The discovery
of the deficiency of 7-dehydrocholesterol reductase as a causative factor of the SLO
syndrome (Tint et al., 1994) made this syndrome the first true metabolic syndrome
of multiple congenital malformations. A multidisciplinary National Institute of Child
Health and Human Development (NICHD) conference of the SLO syndrome reviewed different
implications of this discovery and proposed further studies in this field. A detailed
report on this conference and abstracts of presentations were provided by Opitz and
de la Cruz (1994). Observations presented at an NICHD RSH/SLOS conference in September
1995 were reviewed by Kelley (1997). Kelley (1998) referred to SLOS as a metabolic
malformation syndrome, but suggested that this may be an exception. Most mutations
that had been related to multiple congenital malformation syndromes, i.e., disturbances
of the body plan, have not been disorders of intermediary metabolism but, instead,
mutations of homeobox genes and other transcriptional regulators and signaling systems.
Opitz et al. (1987) gave a presumedly complete bibliography of the SLO syndrome, which
was updated by Opitz et al. (1994) and included almost 200 references. They concluded
that lumping SLO syndrome with the Pallister-Hall hamartoblastoma syndrome (146510)
is not justified. In a given severe case, differentiation from the Meckel syndrome
(249000) may be a challenge. Herman (2003) reviewed the cholesterol biosynthetic pathway
and the 6 disorders involving enzyme defects in post-squalene cholesterol biosynthesis:
SLOS, desmosterolosis (602398), X-linked dominant chondrodysplasia punctata (CDPX2;
302960), CHILD syndrome (308050), lathosterolosis (607330), and hydrops-ectopic calcification-moth-eaten
skeletal dysplasia (HEM; 215140).;
Inheritance : Autosomal recessive;
Molecular basis : Caused by mutations in the delta-7-dehydrocholesterol reductase gene (DHCR7, 602858.0001);
Laboratory abnormalities : Low cholesterol; Elevated 7-dehydrocholesterol;
Prefixed ID : #270400;
Origin ID : 270400;
UMLS CUI : C0175694;
Automatic exact mappings (from CISMeF team)
- Currated CISMeF NLP mapping
- DO Cross reference
- Genes related to phenotype
- HPO term(s)
- ORDO concept(s)
- Semantic type(s)
- UMLS correspondences (same concept)
