Characteristics are:

- A fibrous band instead of the fibula

- Short deformed leg

- Absence of the lateral part of the ankle joint (due to absence of the distal end of the fibula), and what is left is unstable; the foot has an equinovalgus deformity

- Possible absence of part of the foot requiring surgical intervention to bring the foot into normal function, or amputation.

- Possible absence of one or two toes on the foot

- Possible conjoined toes or metatarsals

Partial or total absence of fibula is among the most frequent limb anomalies. It is the most common long bone deficiency and is the most common skeletal deformity in the leg. It most often is unilateral (present only on one side). It may also present as bilateral (affecting both legs). Paraxial fibular hemimelia is the most common manifestation in which only the postaxial portion of the limb is affected. It is commonly seen as a complete terminal deficiency, where the lateral rays of the foot are also affected. Hemimelia can also be intercalary in which case the foot remains unaffected. Although the missing bone is easily identified, this condition is not simply a missing bone. Males are affected twice as often as females in most series.

This is much more common, but is not usually of any major health consequence, as long as the other kidney is healthy.

It may be associated with an increased incidence of Müllerian duct abnormalities, which are abnormalities of the development of the female reproductive tract and can be a cause of infertility, blocked menstrual flow (hematocolpos), increased need for Caesarean sections, or other problems. Herlyn-Werner-Wunderlich syndrome is one such syndrome in which unilaterial renal agenesis is combined with a blind hemivagina and uterus didelphys. Up to 40% of women with a urogenital tract anomaly also have an associated renal tract anomaly.

Adults with unilateral renal agenesis have considerably higher chances of hypertension (high blood pressure). People with this condition are advised to approach contact sports with caution.

The odds of a person being born with unilateral renal agenesis are approximately 1 in 750.

Facial femoral syndrome is a rare congenital disorder. It is also known as femoral dysgenesis, bilateral femoral dysgenesis, bilateral-Robin anomaly and femoral hypoplasia-unusual facies syndrome. The main features of this disorder are underdeveloped thigh bones (femurs) and unusual facial features.

When a diagnosis of multicystic kidney is made in utero by ultrasound, the disease is found to be bilateral in many cases. Those with bilateral disease often have other severe deformities or polysystemic malformation syndromes. In bilateral cases, the newborn has the classic characteristic of Potter's syndrome.

The bilateral condition is incompatible with survival, as the contralateral system frequently is abnormal as well. Contralateral ureteropelvic junction obstruction is found in 3% to 12% of infants with multicystic kidney and contralateral vesicoureteral reflux is seen even more often, in 18% to 43% of infants. Because the high incidence of reflux, voiding cystourethrography usually has been considered advisable in all newborns with a multicystic kidney.

Bilateral renal agenesis is a condition in which both kidneys of a fetus fail to develop during gestation. It is one causative agent of Potter sequence. This absence of kidneys causes oligohydramnios, a deficiency of amniotic fluid in a pregnant woman, which can place extra pressure on the developing baby and cause further malformations. The condition is frequently, but not always the result of a genetic disorder, and is more common in infants born to one or more parents with a malformed or absent kidney.

The diagnosis is based on the combination of unusual facial features and the dysplastic or absent femurs.

Diagnosis may be made antenatally.

Fibular hemimelia or longitudinal fibular deficiency is "the congenital absence of the fibula and it is the most common congenital absence of long bone of the extremities." It is the shortening of the fibula at birth, or the complete lack thereof. In humans, the disorder can be noted by ultrasound in utero to prepare for amputation after birth or complex bone lengthening surgery. The amputation usually takes place at six months with removal of portions of the legs to prepare them for prosthetic use. The other treatments which include repeated corrective osteotomies and leg-lengthening surgery (Ilizarov apparatus) are costly and associated with residual deformity.

Say syndrome is a condition characterized by bilateral acromial dimples.

Microphthalmia–dermal aplasia–sclerocornea syndrome (also known as "MIDAS syndrome") is a condition characterized by linear skin lesions.

MLS is a rare X-linked dominant male-lethal disease characterized by unilateral or bilateral microphthalmia and linear skin defects in affected females, and in utero lethality for affected males. It can be associated with "HCCS", but mutations in the MCCS gene cause Microphthalmia with Linear Skin Defects Syndrome.

Congenital onychodysplasia of the index fingers is defined by the presence of the condition at birth, either unilateral or bilateral index finger involvement, variable distortion of the nail or lunula, and polyonychia, micronychia, anonychia, hemionychogryphosis, or malalignment.

- The original paper was

- This condition is also called Iso-Kikuchi syndrome, since Iso was the first author who published it in a Japanese paper.

The most prominent and extensively documented findings of Weismann-Netter-Stuhl syndrome are on plain radiographs of the bones. Findings include bilateral and symmetric anterior bowing of both tibiae and fibulae, lateral bowing of the tibiae, femoral bowing, and squaring of iliac and pelvis bones.

Multicystic dysplastic kidney (MCDK) is a condition that results from the malformation of the kidney during fetal development. The kidney consists of irregular cysts of varying sizes. Multicystic dysplastic kidney is a common type of renal cystic disease, and it is a cause of an abdominal mass in infants.

Weismann-Netter-Stuhl syndrome, also known as Weismann-Netter Syndrome or more technically by the term tibioperoneal diaphyseal toxopachyosteosis, is a rare disorder characterized by bowing of the lower legs and an abnormal thickening of thinner bone in the leg.

The main sign is anterior bowing and posterior cortical thickening of the diaphyses of both the tibiae and fibulae. It is thought to be inherited in an autosomal dominant fashion, and is most often bilateral and symmetric in nature. Associated features include dwarfism and mild intellectual disability, as well as a process known as tibialization of the fibulae, which involves thickening and enlargement of these bones to an extent resembling the tibiae. The combination of the presence of tibialization of the fibulae, which is highly specific for the disorder, and the absence of laboratory abnormalities ruling out alternative diagnoses including rickets, essentially confirms the diagnosis.

Patients with this syndrome are shorter than the average person and may not develop hair in many places, including in the facial, leg and pubic areas. Patients also have eye problems including reduced eye size, bilateral cataracts and glaucoma.

It can be associated with sleep apnea.

It can complicate intubation.

Low-set ears are ears with depressed positioning of the pinna two or more standard deviations below the population average.

It can be associated with conditions such as:

- Down's syndrome

- Turner Syndrome

- Noonan syndrome

- Patau syndrome

- DiGeorge syndrome

- Cri du chat syndrome

- Edwards syndrome

- Fragile X syndrome

It is usually bilateral, but can be unilateral in Goldenhar syndrome.

Young–Madders syndrome is detectable from the fetal stage of development largely due to the distinctive consequences of holoprosencephaly, a spectrum of defects or malformations of the brain and face. Facial defects which may manifest in the eyes, nose, and upper lip, featuring cyclopia, anosmia, or in the growth of only a single central incisor, and severe overlapping of the bones of the skull. Cardiac and in some cases pulmonary deformities are present. Another signature deformity is bilateral polydactyly, and many patients also suffer from hypoplasia and genital deformities.

This atavistic feature is so called because its description was first published by Charles Darwin in the opening pages of "The Descent of Man, and Selection in Relation to Sex", as evidence of a vestigial feature indicating common ancestry among primates which have pointy ears. However, Darwin himself named it the Woolnerian tip, after Thomas Woolner, a British sculptor who had depicted it in one of his sculptures and had first theorised that it was an atavistic feature.

Scrotal ultrasonography and transrectal ultrasonography (TRUS) are useful in detecting uni- or bilateral CBAVD, which may be associated with visible abnormalities or agenesis of the epididymis, seminal vesicles or kidneys.

Congenital absence of the vas deferens (CAVD) is a condition in which the vasa deferentia reproductive organs, fail to form properly prior to birth. It may either be unilateral (CUAVD) or bilateral (CBAVD).

Hallermann–Streiff syndrome is a congenital disorder that affects growth, cranial development, hair growth and dental development. There are fewer than 200 people with the syndrome worldwide. An organization supporting people with the Hallermann–Streiff syndrome is the Germany-based "Schattenkinder e.V."

Darwin's tubercle (or auricular tubercle) is a congenital ear condition which often presents as a thickening on the helix at the junction of the upper and middle thirds.

Young–Madders syndrome, alternatively known as Pseudotrisomy 13 syndrome or holoprosencephaly–polydactyly syndrome, is a genetic disorder resulting from defective and duplicated chromosomes which result in holoprosencephaly, polydactyly, facial malformations and mental retardation, with a significant variance in the severity of symptoms being seen across known cases. Many cases often suffer with several other genetic disorders, and some have presented with hypoplasia, cleft lip, cardiac lesions and other heart defects. In one case in 1991 and another in 2000 the condition was found in siblings who were the product of incest. Many cases are diagnosed prenatally and often in siblings. Cases are almost fatal in the prenatal stage with babies being stillborn.

Though it is now thought that earlier cases were misdiagnosed as other genetic disorders with similar pathology—such as Smith–Lemli–Opitz syndrome—the earliest publicised recognition of the condition as a new, hitherto unclassified, genetic disorder was made by two British doctors in Leicester in 1987. Though they identified the condition, later named for them, they did not identify the genetic anomalies responsible but suspected a link with trisomy 13 due to the similar symptoms. With only one or two occurrences documented towards the end of the decade, a group of eight doctors published a five-patient case-study in 1991 which identified the likely chromosomal factors that caused the condition, similar to but distinct from trisomy 13, and gave it the name 'holoprosencephaly–polydactyly syndrome' based on its two most prolific presenting conditions. Later research showed that the condition could manifest in patients with normal karyotypes, without duplication of the chromosomes, and the most recent genetic research implicates problems with the gene code FBXW11 as a likely cause.

Marcus Gunn phenomenon, also known as Marcus Gunn jaw-winking or trigemino-oculomotor synkinesis, is an autosomal dominant condition with incomplete penetrance, in which nursing infants will have rhythmic upward jerking of their upper eyelid. This condition is characterized as a synkinesis: when two or more muscles that are independently innervated have either simultaneous or coordinated movements.

Common physiologic examples of synkineses occur during sucking, chewing, or conjugate eye movements. There are also several abnormal cranial nerve synkineses, both acquired and congenital. Marcus Gunn jaw-winking is an example of a pathologic congenital synkinesis.

First described by the ophthalmologist Marcus Gunn in 1883, this condition presents in approximately 5% of neonates with congenital ptosis. This condition has been associated with amblyopia (in 54% of cases), anisometropia (26%), and strabismus (56%).

The symptoms of ichthyosis hystrix Curth-Macklin are similar to epidermolytic hyperkeratosis (NPS-2 type) but there is no blistering and the hyperkeratosis is verrucous or spine-like. The hyperkeratosis is brown-grey in colour and is most obvious on the arms and legs. It is an autosomal dominant condition and can be caused by errors to the KRT1 gene. It is named after Helen Ollendorff Curth (1899-1982), a German-Jewish dermatologist, and Madge Thurlow Macklin (1893–1962), an American medical geneticist, and is one of the first syndromes named after two women.

The diagnosis of PMG is merely descriptive and is not a disease in itself, nor does it describe the underlying cause of the brain malformation.

Polymicrogyria may be just one piece of a syndrome of developmental abnormalities, because children born with it may suffer from a wide spectrum of other problems, including global developmental disabilities, mild to severe mental retardation, motor dysfunctions including speech and swallowing problems, respiratory problems, and seizures. Though it is difficult to make a predictable prognosis for children with the diagnosis of PMG, there are some generalized clinical findings according to the areas of the brain that are affected.

- Bilateral frontal polymicrogyria (BFP) – Cognitive and motor delay, spastic quadriparesis, epilepsy

- Bilateral frontoparietal polymicrogyria (BFPP) – Severe cognitive and motor delay, seizures, dysconjugate gaze, cerebellar dysfunction

- Bilateral perisylvian polymicrogyria (BPP) – Pseudobulbar signs, cognitive impairment, epilepsy, some with arthrogryposis or lower motor neuron disease

- Bilateral parasagittal parieto-occipital polymicrogyria (BPPP) – Partial seizures, some with mental retardation

- Bilateral generalized polymicrogyria (BGP) – Cognitive and motor delay of variable severity, seizures