Low-set ears, and Ascites

This syndrome is characterised by severe hypotonia, lactic academia and congenital hyperammonaemia.

HYPOTONIA WITH LACTIC ACIDEMIA AND HYPERAMMONEMIA Is also known as combined oxidative phosphorylation defect type 5|coxpd5

• Seizures
• Generalized hypotonia
• Microcephaly
• Growth delay
• Muscular hypotonia

SOURCES: MESH ORPHANET OMIM MENDELIAN

Complex lethal osteochondrodysplasia of the Symoens-Barnes-Gistelinck type is characterized by severe skeletal osteopenia, microcephaly, multiple fractures, and congenital anomalies including ascites, pleural effusion, and intracranial ventriculomegaly (Symoens et al., 2015).

COMPLEX LETHAL OSTEOCHONDRODYSPLASIA Is also known as complex lethal osteochondrodysplasia, symoens-barnes-gistelinck type

• Microcephaly
• Growth delay
• Hypertelorism
• Micrognathia
• Cleft palate

SOURCES: ORPHANET OMIM MENDELIAN

ALG9-CDG is a form of congenital disorders of N-linked glycosylation characterized by progressive microcephaly, hypotonia, developmental delay, drug-resistant infantile epilepsy, and hepatomegaly. Additional features that may be observed include failure to thrive, pericardial effusion, renal cysts, skeletal dysplasia, facial dysmorphism (frontal bossing, hypertelorism, depressed nasal bridge, low-seated ears, large mouth) and hydrops fetalis (see this term). The disease is caused by loss-of-function mutations in the gene ALG9 (11q23).

ALG9-CDG Is also known as cdg syndrome type il|cdg-il|carbohydrate deficient glycoprotein syndrome type 1l|cdg il|cdgil|congenital disorder of glycosylation type 1l|cdg1l|mannosyltransferase 7-9 deficiency

• Intellectual disability
• Seizures
• Global developmental delay
• Generalized hypotonia
• Microcephaly

SOURCES: OMIM ORPHANET MENDELIAN

Mucopolysaccharidosis type 2 (MPS2, see this term), severe form (MPS2S), is associated with a massive accumulation of glycosaminoglycans and a wide variety of symptoms including a rapidly progressive cognitive decline; it is most often fatal in the second or third decade.

MUCOPOLYSACCHARIDOSIS TYPE 2, SEVERE FORM Is also known as mucopolysaccharidosis type ii, severe form|mps2a|iduronate 2-sulfatase deficiency type a|mucopolysaccharidosis type 2a|hunter syndrome type a|mpsiia|mucopolysaccharidosis type iia

• Intellectual disability
• Seizures
• Global developmental delay
• Short stature
• Hearing impairment

SOURCES: ORPHANET MENDELIAN

Acrocephalopolydactylous dysplasia, or Elejalde syndrome, is a lethal multiple congenital disorder characterized by increased birth weight, globular body with thick skin, organomegaly, and fibrosis in multiple tissues (summary by Phadke et al., 2011).

ACROCEPHALOPOLYDACTYLOUS DYSPLASIA Is also known as elejalde syndrome

• Intellectual disability
• Seizures
• Global developmental delay
• Ataxia
• Hypertelorism

SOURCES: OMIM MENDELIAN

Short rib-polydactyly syndrome (SRPS), Beemer-Langer type is an extremely rare type of SRPS developing prenatally or immediately after birth and characterized by short and narrow thorax with horizontally oriented ribs. Other bone features include small iliac bones, short tubular bones, bowing of long bones and rarely pre- and post-axial polydactyly. Brain defects are common and some cases of cleft lip, absent internal genitalia and renal, biliary and pancreatic cysts have been reported. The course is rapidly fatal.

SHORT RIB-POLYDACTYLY SYNDROME, BEEMER-LANGER TYPE Is also known as short rib syndrome, beemer type|srps iv|short rib-polydactyly syndrome type 4|short rib-polydactyly syndrome, type iv|beemer-langer syndrome|srps4

• Hypertelorism
• Abnormal facial shape
• Cleft palate
• Low-set ears
• Epicanthus

SOURCES: ORPHANET MESH OMIM MENDELIAN

Perlman syndrome is characterized principally by polyhydramnios, neonatal macrosomia, bilateral renal tumours (hamartomas with or without nephroblastomatosis), hypertrophy of the islets of Langerhans and facial dysmorphism.

PERLMAN SYNDROME Is also known as nephroblastomatosis, fetal ascites, macrosomia, and wilms tumor|nephroblastomatosis-fetal ascites-macrosomia-wilms tumor syndrome|renal hamartomas, nephroblastomatosis, and fetal gigantism

• Intellectual disability
• Seizures
• Global developmental delay
• Generalized hypotonia
• Scoliosis

SOURCES: MESH ORPHANET OMIM MENDELIAN

D-bifunctional protein deficiency is a disorder of peroxisomal fatty acid beta-oxidation. See also peroxisomal acyl-CoA oxidase deficiency (OMIM ), caused by mutation in the ACOX1 gene (OMIM ) on chromosome 17q25. The clinical manifestations of these 2 deficiencies are similar to those of disorders of peroxisomal assembly, including X-linked adrenoleukodystrophy (ALD ), Zellweger cerebrohepatorenal syndrome (see {214100}) and neonatal adrenoleukodystrophy (NALD; see {601539}) (Watkins et al., 1995).DBP deficiency has been classified into 3 subtypes depending upon the deficient enzyme activity. Type I is a deficiency of both 2-enoyl-CoA hydratase and 3-hydroxyacyl-CoA dehydrogenase; type II is a deficiency of hydratase activity alone; and type III is a deficiency of dehydrogenase activity alone. Virtually all patients with types I, II, and III have a severe phenotype characterized by infantile-onset of hypotonia, seizures, and abnormal facial features, and most die before age 2 years. McMillan et al. (2012) proposed a type IV deficiency on the basis of less severe features; these patients have a phenotype reminiscent of Perrault syndrome (PRLTS1 ). Pierce et al. (2010) noted that Perrault syndrome and DBP deficiency overlap clinically and suggested that DBP deficiency may be underdiagnosed.

D-BIFUNCTIONAL PROTEIN DEFICIENCY Is also known as peroxisomal bifunctional enzyme deficiency|dbp deficiency|17-beta-hydroxysteroid dehydrogenase iv deficiency|pbfe deficiency

• Seizures
• Global developmental delay
• Generalized hypotonia
• Hearing impairment
• Hypertelorism

SOURCES: ORPHANET OMIM MENDELIAN

Takenouchi-Kosaki syndrome is a highly heterogeneous autosomal dominant complex congenital developmental disorder affecting multiple organ systems. The core phenotype includes delayed psychomotor development with variable intellectual disability, dysmorphic facial features, and cardiac, genitourinary, and hematologic or lymphatic defects, including thrombocytopenia and lymphedema. Additional features may include abnormalities on brain imaging, skeletal anomalies, and recurrent infections. Some patients have a milder disease course reminiscent of Noonan syndrome (see, e.g., NS1, {163950}) (summary by Martinelli et al., 2018).

MACROTHROMBOCYTOPENIA-LYMPHEDEMA-DEVELOPMENTAL DELAY-FACIAL DYSMORPHISM-CAMPTODACTYLY SYNDROME Is also known as takenouchi-kosaki syndrome|macrothrombocytopenia and mental retardation syndrome

• Intellectual disability
• Seizures
• Global developmental delay
• Generalized hypotonia
• Hearing impairment

SOURCES: OMIM ORPHANET MENDELIAN

Fetal Gaucher disease is the perinatal lethal form of Gaucher disease (GD; see this term).

FETAL GAUCHER DISEASE Is also known as perinatal lethal gaucher disease|gaucher disease, collodion type

• Seizures
• Generalized hypotonia
• Microcephaly
• Hypertelorism
• Micrognathia

SOURCES: ORPHANET MESH OMIM MENDELIAN